diff --git a/CMake/CurlTests.c b/CMake/CurlTests.c
index f43521bfd6..e8117410fd 100644
--- a/CMake/CurlTests.c
+++ b/CMake/CurlTests.c
@@ -65,7 +65,7 @@ int main(void)
 #include <netdb.h>
 int main(void)
 {
-  const char *address = "localhost";
+  static const char address[] = "localhost";
   struct hostent h;
   int rc = 0;
 #if   defined(HAVE_GETHOSTBYNAME_R_3) || \
diff --git a/docs/examples/10-at-a-time.c b/docs/examples/10-at-a-time.c
index d0982e0d41..34572e438b 100644
--- a/docs/examples/10-at-a-time.c
+++ b/docs/examples/10-at-a-time.c
@@ -30,7 +30,7 @@
 
 #include <curl/curl.h>
 
-static const char *urls[] = {
+static const char * const urls[] = {
   "https://01.example/",
   "https://02.example/",
   "https://03.example/",
diff --git a/docs/examples/crawler.c b/docs/examples/crawler.c
index 21cdb5fcff..595375614e 100644
--- a/docs/examples/crawler.c
+++ b/docs/examples/crawler.c
@@ -47,7 +47,7 @@ static int max_total = 20000;
 static int max_requests = 500;
 static size_t max_link_per_page = 5;
 static int follow_relative_links = 0;
-static const char *start_page = "https://www.reuters.com/";
+static const char start_page[] = "https://www.reuters.com/";
 
 static int pending_interrupt = 0;
 static void sighandler(int dummy)
diff --git a/docs/examples/ephiperfifo.c b/docs/examples/ephiperfifo.c
index 292bfc741e..de86690ef4 100644
--- a/docs/examples/ephiperfifo.c
+++ b/docs/examples/ephiperfifo.c
@@ -303,7 +303,9 @@ static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
 {
   struct GlobalInfo *g = (struct GlobalInfo *)cbp;
   struct SockInfo *fdp = (struct SockInfo *)sockp;
-  const char *whatstr[] = { "none", "IN", "OUT", "INOUT", "REMOVE" };
+  static const char * const whatstr[] = {
+    "none", "IN", "OUT", "INOUT", "REMOVE"
+  };
 
   fprintf(MSG_OUT, "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
   if(what == CURL_POLL_REMOVE) {
@@ -407,7 +409,7 @@ static void fifo_cb(struct GlobalInfo *g, int revents)
 static int init_fifo(struct GlobalInfo *g)
 {
   struct stat st;
-  static const char *fifo = "hiper.fifo";
+  static const char fifo[] = "hiper.fifo";
   curl_socket_t sockfd;
   struct epoll_event epev;
 
diff --git a/docs/examples/evhiperfifo.c b/docs/examples/evhiperfifo.c
index 079eab1e8a..32f92f9415 100644
--- a/docs/examples/evhiperfifo.c
+++ b/docs/examples/evhiperfifo.c
@@ -267,7 +267,9 @@ static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
 {
   struct GlobalInfo *g = (struct GlobalInfo *)cbp;
   struct SockInfo *fdp = (struct SockInfo *)sockp;
-  const char *whatstr[] = { "none", "IN", "OUT", "INOUT", "REMOVE" };
+  static const char * const whatstr[] = {
+    "none", "IN", "OUT", "INOUT", "REMOVE"
+  };
 
   printf("%s e %p s %d what %d cbp %p sockp %p\n",
          __PRETTY_FUNCTION__, e, s, what, cbp, sockp);
@@ -378,7 +380,7 @@ static void fifo_cb(EV_P_ struct ev_io *w, int revents)
 static int init_fifo(struct GlobalInfo *g)
 {
   struct stat st;
-  static const char *fifo = "hiper.fifo";
+  static const char fifo[] = "hiper.fifo";
   curl_socket_t sockfd;
 
   fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
diff --git a/docs/examples/ghiper.c b/docs/examples/ghiper.c
index fd6041761e..79516ccd82 100644
--- a/docs/examples/ghiper.c
+++ b/docs/examples/ghiper.c
@@ -258,7 +258,9 @@ static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
 {
   struct GlobalInfo *g = (struct GlobalInfo *)cbp;
   struct SockInfo *fdp = (struct SockInfo *)sockp;
-  static const char *whatstr[] = { "none", "IN", "OUT", "INOUT", "REMOVE" };
+  static const char * const whatstr[] = {
+    "none", "IN", "OUT", "INOUT", "REMOVE"
+  };
 
   MSG_OUT("socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
   if(what == CURL_POLL_REMOVE) {
@@ -395,8 +397,8 @@ static gboolean fifo_cb(GIOChannel *ch, GIOCondition condition, gpointer data)
 
 int init_fifo(void)
 {
+  static const char fifo[] = "hiper.fifo";
   struct stat st;
-  const char *fifo = "hiper.fifo";
   int socket;
 
   if(!lstat(fifo, &st)) {
diff --git a/docs/examples/hiperfifo.c b/docs/examples/hiperfifo.c
index 96719530cf..cc27799012 100644
--- a/docs/examples/hiperfifo.c
+++ b/docs/examples/hiperfifo.c
@@ -270,7 +270,9 @@ static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
 {
   struct GlobalInfo *g = (struct GlobalInfo *)cbp;
   struct SockInfo *fdp = (struct SockInfo *)sockp;
-  const char *whatstr[] = { "none", "IN", "OUT", "INOUT", "REMOVE" };
+  static const char * const whatstr[] = {
+    "none", "IN", "OUT", "INOUT", "REMOVE"
+  };
 
   fprintf(MSG_OUT, "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
   if(what == CURL_POLL_REMOVE) {
@@ -376,7 +378,7 @@ static void fifo_cb(int fd, short event, void *arg)
 }
 
 /* Create a named pipe and tell libevent to monitor it */
-static const char *fifo = "hiper.fifo";
+static const char fifo[] = "hiper.fifo";
 static int init_fifo(struct GlobalInfo *g)
 {
   struct stat st;
diff --git a/docs/examples/imap-append.c b/docs/examples/imap-append.c
index 77cf2bc02a..c530bbb9c8 100644
--- a/docs/examples/imap-append.c
+++ b/docs/examples/imap-append.c
@@ -40,7 +40,7 @@
 #define TO   "<addressee@example.net>"
 #define CC   "<info@example.org>"
 
-static const char *payload_text =
+static const char payload_text[] =
   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
   "To: " TO "\r\n"
   "From: " FROM "(Example User)\r\n"
@@ -111,7 +111,7 @@ int main(void)
     curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
     curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
 
-    filesize = strlen(payload_text);
+    filesize = sizeof(payload_text) - 1;
     if(filesize <= LONG_MAX)
       infilesize = (long)filesize;
     curl_easy_setopt(curl, CURLOPT_INFILESIZE, infilesize);
diff --git a/docs/examples/maxconnects.c b/docs/examples/maxconnects.c
index 7ef29828ea..b52f1fcc3f 100644
--- a/docs/examples/maxconnects.c
+++ b/docs/examples/maxconnects.c
@@ -39,7 +39,7 @@ int main(void)
 
   curl = curl_easy_init();
   if(curl) {
-    const char *urls[] = {
+    static const char * const urls[] = {
       "https://example.com/",
       "https://curl.se/",
       "https://www.example/",
diff --git a/docs/examples/postinmemory.c b/docs/examples/postinmemory.c
index c4d9abcc11..7f18e8e5f5 100644
--- a/docs/examples/postinmemory.c
+++ b/docs/examples/postinmemory.c
@@ -61,7 +61,7 @@ int main(void)
   CURL *curl;
   CURLcode result;
   struct MemoryStruct chunk;
-  static const char *postthis = "Field=1&Field=2&Field=3";
+  static const char postthis[] = "Field=1&Field=2&Field=3";
 
   result = curl_global_init(CURL_GLOBAL_ALL);
   if(result != CURLE_OK)
@@ -87,7 +87,7 @@ int main(void)
     curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postthis);
 
     /* if we do not provide POSTFIELDSIZE, libcurl calls strlen() by itself */
-    curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)strlen(postthis));
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)sizeof(postthis) - 1);
 
     /* Perform the request, result gets the return code */
     result = curl_easy_perform(curl);
diff --git a/docs/examples/sendrecv.c b/docs/examples/sendrecv.c
index 2777ca0a6d..a3539adb3c 100644
--- a/docs/examples/sendrecv.c
+++ b/docs/examples/sendrecv.c
@@ -77,8 +77,8 @@ int main(void)
 {
   CURL *curl;
   /* Minimalistic http request */
-  const char *request = "GET / HTTP/1.0\r\nHost: example.com\r\n\r\n";
-  size_t request_len = strlen(request);
+  static const char request[] = "GET / HTTP/1.0\r\nHost: example.com\r\n\r\n";
+  static const size_t request_len = sizeof(request) - 1;
 
   CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
   if(result != CURLE_OK)
diff --git a/docs/examples/sepheaders.c b/docs/examples/sepheaders.c
index c9fee6c2ba..011eae1aea 100644
--- a/docs/examples/sepheaders.c
+++ b/docs/examples/sepheaders.c
@@ -53,9 +53,9 @@ int main(void)
   /* init the curl session */
   curl = curl_easy_init();
   if(curl) {
-    static const char *headerfilename = "head.out";
+    static const char headerfilename[] = "head.out";
     FILE *headerfile;
-    static const char *bodyfilename = "body.out";
+    static const char bodyfilename[] = "body.out";
     FILE *bodyfile;
 
     /* set URL to get */
diff --git a/docs/examples/sftpuploadresume.c b/docs/examples/sftpuploadresume.c
index 153883640b..e5d14a8459 100644
--- a/docs/examples/sftpuploadresume.c
+++ b/docs/examples/sftpuploadresume.c
@@ -134,8 +134,8 @@ int main(void)
 
   curl = curl_easy_init();
   if(curl) {
-    const char *remote = "sftp://user:pass@example.com/path/filename";
-    const char *filename = "filename";
+    static const char remote[] = "sftp://user:pass@example.com/path/filename";
+    static const char filename[] = "filename";
 
     if(!sftpResumeUpload(curl, remote, filename)) {
       printf("resumed upload using curl %s failed\n", curl_version());
diff --git a/docs/examples/simplepost.c b/docs/examples/simplepost.c
index d2540151ce..fb85677c31 100644
--- a/docs/examples/simplepost.c
+++ b/docs/examples/simplepost.c
@@ -32,7 +32,7 @@
 
 int main(void)
 {
-  static const char *postthis = "moo mooo moo moo";
+  static const char postthis[] = "moo mooo moo moo";
 
   CURL *curl;
 
@@ -46,7 +46,7 @@ int main(void)
     curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postthis);
 
     /* if we do not provide POSTFIELDSIZE, libcurl calls strlen() by itself */
-    curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)strlen(postthis));
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)sizeof(postthis) - 1);
 
     /* Perform the request, result gets the return code */
     result = curl_easy_perform(curl);
diff --git a/docs/examples/simplessl.c b/docs/examples/simplessl.c
index 24e08c4c71..45db65a05d 100644
--- a/docs/examples/simplessl.c
+++ b/docs/examples/simplessl.c
@@ -55,9 +55,9 @@ int main(void)
   FILE *headerfile;
   const char *pPassphrase = NULL;
 
-  static const char *pCertFile = "testcert.pem";
-  static const char *pCACertFile = "cacert.pem";
-  static const char *pHeaderFile = "dumpit";
+  static const char pCertFile[] = "testcert.pem";
+  static const char pCACertFile[] = "cacert.pem";
+  static const char pHeaderFile[] = "dumpit";
 
   const char *pKeyName;
   const char *pKeyType;
diff --git a/docs/examples/smtp-authzid.c b/docs/examples/smtp-authzid.c
index fe91ba5e63..0260452990 100644
--- a/docs/examples/smtp-authzid.c
+++ b/docs/examples/smtp-authzid.c
@@ -48,7 +48,7 @@
 #define SENDER_MAIL "Kurt " SENDER_ADDR
 #define TO_MAIL     "A Receiver " TO_ADDR
 
-static const char *payload_text =
+static const char payload_text[] =
   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
   "To: " TO_MAIL "\r\n"
   "From: " FROM_MAIL "\r\n"
diff --git a/docs/examples/smtp-mail.c b/docs/examples/smtp-mail.c
index b1590fd3af..618123ab5e 100644
--- a/docs/examples/smtp-mail.c
+++ b/docs/examples/smtp-mail.c
@@ -45,7 +45,7 @@
 #define TO_MAIL   "A Receiver " TO_ADDR
 #define CC_MAIL   "John CC Smith " CC_ADDR
 
-static const char *payload_text =
+static const char payload_text[] =
   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
   "To: " TO_MAIL "\r\n"
   "From: " FROM_MAIL "\r\n"
diff --git a/docs/examples/smtp-mime.c b/docs/examples/smtp-mime.c
index 0ddba4ebb7..4d54532559 100644
--- a/docs/examples/smtp-mime.c
+++ b/docs/examples/smtp-mime.c
@@ -41,7 +41,7 @@
 #define TO   "<addressee@example.net>"
 #define CC   "<info@example.org>"
 
-static const char *headers_text[] = {
+static const char * const headers_text[] = {
   "Date: Tue, 22 Aug 2017 14:08:43 +0100",
   "To: " TO,
   "From: " FROM " (Example User)",
@@ -82,7 +82,7 @@ int main(void)
     curl_mime *mime;
     curl_mime *alt;
     curl_mimepart *part;
-    const char **cpp;
+    const char * const *cpp;
 
     /* This is the URL for your mailserver */
     curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");
diff --git a/docs/examples/smtp-multi.c b/docs/examples/smtp-multi.c
index 86545a1ef3..9d76a57fe7 100644
--- a/docs/examples/smtp-multi.c
+++ b/docs/examples/smtp-multi.c
@@ -38,7 +38,7 @@
 #define TO_MAIL   "<recipient@example.com>"
 #define CC_MAIL   "<info@example.com>"
 
-static const char *payload_text =
+static const char payload_text[] =
   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
   "To: " TO_MAIL "\r\n"
   "From: " FROM_MAIL "\r\n"
diff --git a/docs/examples/smtp-ssl.c b/docs/examples/smtp-ssl.c
index 9cac9ecd52..172f66b8da 100644
--- a/docs/examples/smtp-ssl.c
+++ b/docs/examples/smtp-ssl.c
@@ -42,7 +42,7 @@
 #define TO_MAIL   "<recipient@example.com>"
 #define CC_MAIL   "<info@example.com>"
 
-static const char *payload_text =
+static const char payload_text[] =
   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
   "To: " TO_MAIL "\r\n"
   "From: " FROM_MAIL "\r\n"
diff --git a/docs/examples/smtp-tls.c b/docs/examples/smtp-tls.c
index da452318a6..c3c992717b 100644
--- a/docs/examples/smtp-tls.c
+++ b/docs/examples/smtp-tls.c
@@ -42,7 +42,7 @@
 #define TO_MAIL   "<recipient@example.com>"
 #define CC_MAIL   "<info@example.com>"
 
-static const char *payload_text =
+static const char payload_text[] =
   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
   "To: " TO_MAIL "\r\n"
   "From: " FROM_MAIL "\r\n"
diff --git a/docs/examples/synctime.c b/docs/examples/synctime.c
index 2c7501d4db..8e9adf1f3f 100644
--- a/docs/examples/synctime.c
+++ b/docs/examples/synctime.c
@@ -99,10 +99,10 @@ static int AutoSyncTime;
 static SYSTEMTIME SYSTime;
 static SYSTEMTIME LOCALTime;
 
-static const char *DayStr[] = {
+static const char * const DayStr[] = {
   "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
 };
-static const char *MthStr[] = {
+static const char * const MthStr[] = {
   "Jan", "Feb", "Mar", "Apr", "May", "Jun",
   "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 };
diff --git a/docs/examples/url2file.c b/docs/examples/url2file.c
index ce8805a40e..1216575638 100644
--- a/docs/examples/url2file.c
+++ b/docs/examples/url2file.c
@@ -44,7 +44,7 @@ static size_t write_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 
 int main(int argc, const char *argv[])
 {
-  static const char *pagefilename = "page.out";
+  static const char pagefilename[] = "page.out";
 
   CURLcode result;
   CURL *curl;
diff --git a/docs/examples/websocket-updown.c b/docs/examples/websocket-updown.c
index 85a7e74ea3..495c4b7166 100644
--- a/docs/examples/websocket-updown.c
+++ b/docs/examples/websocket-updown.c
@@ -88,7 +88,7 @@ int main(int argc, const char *argv[])
 {
   CURL *curl;
   struct read_ctx rctx;
-  const char *payload = "Hello, friend!";
+  static const char payload[] = "Hello, friend!";
 
   CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
   if(result != CURLE_OK)
@@ -108,7 +108,7 @@ int main(int argc, const char *argv[])
     curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_cb);
     /* tell curl that we want to send the payload */
     rctx.curl = curl;
-    rctx.blen = strlen(payload);
+    rctx.blen = sizeof(payload) - 1;
     memcpy(rctx.buf, payload, rctx.blen);
     curl_easy_setopt(curl, CURLOPT_READDATA, &rctx);
     curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
diff --git a/lib/cf-h1-proxy.c b/lib/cf-h1-proxy.c
index f1e5c7a42a..b425249588 100644
--- a/lib/cf-h1-proxy.c
+++ b/lib/cf-h1-proxy.c
@@ -329,7 +329,7 @@ static CURLcode on_resp_header_udp(struct Curl_cfilter *cf,
             k->httpcode);
     }
     else {
-      const char *p = header + strlen("Content-Length:");
+      const char *p = header + CURL_CSTRLEN("Content-Length:");
       if(curlx_str_numblanks(&p, &ts->cl)) {
         failf(data, "Unsupported Content-Length value");
         return CURLE_WEIRD_SERVER_REPLY;
@@ -419,7 +419,7 @@ static CURLcode on_resp_header(struct Curl_cfilter *cf,
             k->httpcode);
     }
     else {
-      const char *p = header + strlen("Content-Length:");
+      const char *p = header + CURL_CSTRLEN("Content-Length:");
       if(curlx_str_numblanks(&p, &ts->cl)) {
         failf(data, "Unsupported Content-Length value");
         return CURLE_WEIRD_SERVER_REPLY;
diff --git a/lib/cf-h2-proxy.c b/lib/cf-h2-proxy.c
index be303ffd3e..86e04fc0ec 100644
--- a/lib/cf-h2-proxy.c
+++ b/lib/cf-h2-proxy.c
@@ -574,7 +574,7 @@ static int proxy_h2_on_header(nghttp2_session *session,
     return 0;
   }
 
-  if(namelen == sizeof(HTTP_PSEUDO_STATUS) - 1 &&
+  if(namelen == CURL_CSTRLEN(HTTP_PSEUDO_STATUS) &&
      !memcmp(HTTP_PSEUDO_STATUS, name, namelen)) {
     int http_status;
     struct http_resp *resp;
diff --git a/lib/curl_setup.h b/lib/curl_setup.h
index a91b912f3e..e6d5b8f694 100644
--- a/lib/curl_setup.h
+++ b/lib/curl_setup.h
@@ -1291,10 +1291,14 @@ typedef unsigned int curl_bit;
 #define CURLMAX(x, y) ((x) > (y) ? (x) : (y))
 #define CURLMIN(x, y) ((x) < (y) ? (x) : (y))
 
+/* Convenience macro to provide the length of a string literal size without
+   the null-terminator. Equivalent to strlen() for constant strings. */
+#define CURL_CSTRLEN(x) (sizeof(x) - 1)
+
 /* A convenience macro to provide both the string literal and the length of
    the string literal in one go, useful for functions that take "string,len"
    as their argument */
-#define STRCONST(x) x, sizeof(x) - 1
+#define STRCONST(x) x, CURL_CSTRLEN(x)
 
 #define CURL_ARRAYSIZE(A) (sizeof(A) / sizeof((A)[0]))
 
diff --git a/lib/dict.c b/lib/dict.c
index db25d5a721..2a0053e934 100644
--- a/lib/dict.c
+++ b/lib/dict.c
@@ -153,9 +153,9 @@ static CURLcode dict_do(struct Curl_easy *data, bool *done)
   if(result)
     return result;
 
-  if(curl_strnequal(path, DICT_MATCH, sizeof(DICT_MATCH) - 1) ||
-     curl_strnequal(path, DICT_MATCH2, sizeof(DICT_MATCH2) - 1) ||
-     curl_strnequal(path, DICT_MATCH3, sizeof(DICT_MATCH3) - 1)) {
+  if(curl_strnequal(path, DICT_MATCH, CURL_CSTRLEN(DICT_MATCH)) ||
+     curl_strnequal(path, DICT_MATCH2, CURL_CSTRLEN(DICT_MATCH2)) ||
+     curl_strnequal(path, DICT_MATCH3, CURL_CSTRLEN(DICT_MATCH3))) {
 
     word = strchr(path, ':');
     if(word) {
@@ -200,9 +200,9 @@ static CURLcode dict_do(struct Curl_easy *data, bool *done)
     }
     Curl_xfer_setup_recv(data, FIRSTSOCKET, -1);
   }
-  else if(curl_strnequal(path, DICT_DEFINE, sizeof(DICT_DEFINE) - 1) ||
-          curl_strnequal(path, DICT_DEFINE2, sizeof(DICT_DEFINE2) - 1) ||
-          curl_strnequal(path, DICT_DEFINE3, sizeof(DICT_DEFINE3) - 1)) {
+  else if(curl_strnequal(path, DICT_DEFINE, CURL_CSTRLEN(DICT_DEFINE)) ||
+          curl_strnequal(path, DICT_DEFINE2, CURL_CSTRLEN(DICT_DEFINE2)) ||
+          curl_strnequal(path, DICT_DEFINE3, CURL_CSTRLEN(DICT_DEFINE3))) {
 
     word = strchr(path, ':');
     if(word) {
diff --git a/lib/http.c b/lib/http.c
index c8c0084233..4feb930069 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -5026,7 +5026,7 @@ CURLcode Curl_http_req_to_h2(struct dynhds *h2_headers,
     if(e->namelen == 2 && curl_strequal("TE", e->name)) {
       if(http_TE_has_token(e->value, "trailers"))
         result = Curl_dynhds_add(h2_headers, e->name, e->namelen,
-                                 "trailers", sizeof("trailers") - 1);
+                                 "trailers", CURL_CSTRLEN("trailers"));
     }
     else if(h2_permissible_field(e)) {
       result = Curl_dynhds_add(h2_headers, e->name, e->namelen,
diff --git a/lib/http2.c b/lib/http2.c
index a63fc4a59c..8d4a93cb58 100644
--- a/lib/http2.c
+++ b/lib/http2.c
@@ -1427,7 +1427,7 @@ static int on_header(nghttp2_session *session, const nghttp2_frame *frame,
   if(frame->hd.type == NGHTTP2_PUSH_PROMISE) {
     char *h;
 
-    if((namelen == (sizeof(HTTP_PSEUDO_AUTHORITY) - 1)) &&
+    if((namelen == CURL_CSTRLEN(HTTP_PSEUDO_AUTHORITY)) &&
        !strncmp(HTTP_PSEUDO_AUTHORITY, (const char *)name, namelen)) {
       /* pseudo headers are lower case */
       int rc = 0;
@@ -1503,7 +1503,7 @@ static int on_header(nghttp2_session *session, const nghttp2_frame *frame,
     return 0;
   }
 
-  if(namelen == sizeof(HTTP_PSEUDO_STATUS) - 1 &&
+  if(namelen == CURL_CSTRLEN(HTTP_PSEUDO_STATUS) &&
      !memcmp(HTTP_PSEUDO_STATUS, name, namelen)) {
     /* nghttp2 guarantees :status is received first and only once. */
     char buffer[32];
diff --git a/lib/http_aws_sigv4.c b/lib/http_aws_sigv4.c
index d4ad7cc5f0..bff66a9582 100644
--- a/lib/http_aws_sigv4.c
+++ b/lib/http_aws_sigv4.c
@@ -623,7 +623,7 @@ static CURLcode calc_s3_payload_hash(struct Curl_easy *data,
   }
   else {
     /* Fall back to s3's UNSIGNED-PAYLOAD */
-    size_t len = sizeof(S3_UNSIGNED_PAYLOAD) - 1;
+    size_t len = CURL_CSTRLEN(S3_UNSIGNED_PAYLOAD);
     DEBUGASSERT(len < SHA256_HEX_LENGTH); /* 16 < 65 */
     memcpy(sha_hex, S3_UNSIGNED_PAYLOAD, len);
     sha_hex[len] = 0;
@@ -1143,7 +1143,7 @@ static CURLcode sign_and_set_auth_headers(struct Curl_easy *data,
     goto fail;
 
   /* provider 0 uppercase */
-  Curl_strntoupper(&auth_headers[sizeof("Authorization: ") - 1],
+  Curl_strntoupper(&auth_headers[CURL_CSTRLEN("Authorization: ")],
                    curlx_str(provider0), curlx_strlen(provider0));
 
   curlx_free(data->req.hd_auth);
diff --git a/lib/http_digest.c b/lib/http_digest.c
index 31a9db35a8..90350a1d1e 100644
--- a/lib/http_digest.c
+++ b/lib/http_digest.c
@@ -54,7 +54,7 @@ CURLcode Curl_input_digest(struct Curl_easy *data,
   if(!checkprefix("Digest", header) || !ISBLANK(header[6]))
     return CURLE_AUTH_ERROR;
 
-  header += strlen("Digest");
+  header += CURL_CSTRLEN("Digest");
   curlx_str_passblanks(&header);
 
   return Curl_auth_decode_digest_http_message(header, digest);
diff --git a/lib/http_negotiate.c b/lib/http_negotiate.c
index 891369b5bc..7aaa6878d1 100644
--- a/lib/http_negotiate.c
+++ b/lib/http_negotiate.c
@@ -83,7 +83,7 @@ CURLcode Curl_input_negotiate(struct Curl_easy *data, struct connectdata *conn,
     return CURLE_OUT_OF_MEMORY;
 
   /* Obtain the input token, if any */
-  header += strlen("Negotiate");
+  header += CURL_CSTRLEN("Negotiate");
   curlx_str_passblanks(&header);
 
   len = strlen(header);
diff --git a/lib/http_ntlm.c b/lib/http_ntlm.c
index dc9911fdac..b0a73a6c8a 100644
--- a/lib/http_ntlm.c
+++ b/lib/http_ntlm.c
@@ -65,7 +65,7 @@ CURLcode Curl_input_ntlm(struct Curl_easy *data,
     if(!ntlm)
       return CURLE_OUT_OF_MEMORY;
 
-    header += strlen("NTLM");
+    header += CURL_CSTRLEN("NTLM");
     curlx_str_passblanks(&header);
     if(*header) {
       unsigned char *hdr;
diff --git a/lib/http_proxy.c b/lib/http_proxy.c
index aa20a52ebe..c658b82478 100644
--- a/lib/http_proxy.c
+++ b/lib/http_proxy.c
@@ -215,7 +215,7 @@ static CURLcode http_proxy_create_CONNECT(struct httpreq **preq,
     goto out;
   }
 
-  result = Curl_http_req_make(&req, "CONNECT", sizeof("CONNECT") - 1,
+  result = Curl_http_req_make(&req, "CONNECT", CURL_CSTRLEN("CONNECT"),
                               NULL, 0, authority, strlen(authority),
                               NULL, 0);
   if(result)
@@ -340,7 +340,7 @@ static CURLcode http_proxy_create_CONNECTUDP(struct httpreq **preq,
   }
 
   if(ver == PROXY_HTTP_V1) {
-    result = Curl_http_req_make(&req, "GET", sizeof("GET")-1,
+    result = Curl_http_req_make(&req, "GET", CURL_CSTRLEN("GET"),
                                 proxy_scheme, strlen(proxy_scheme),
                                 authority, strlen(authority),
                                 path, strlen(path));
@@ -348,7 +348,7 @@ static CURLcode http_proxy_create_CONNECTUDP(struct httpreq **preq,
       goto out;
   }
   else if(ver == PROXY_HTTP_V2 || ver == PROXY_HTTP_V3) {
-    result = Curl_http_req_make(&req, "CONNECT", sizeof("CONNECT") - 1,
+    result = Curl_http_req_make(&req, "CONNECT", CURL_CSTRLEN("CONNECT"),
                                 proxy_scheme, strlen(proxy_scheme),
                                 authority, strlen(authority),
                                 path, strlen(path));
diff --git a/lib/imap.c b/lib/imap.c
index 6a48f85152..8f0c297715 100644
--- a/lib/imap.c
+++ b/lib/imap.c
@@ -1357,7 +1357,7 @@ static CURLcode imap_state_select_resp(struct Curl_easy *data,
     size_t len = curlx_dyn_len(&imapc->pp.recvbuf);
     if((len >= 18) && checkprefix("OK [UIDVALIDITY ", &line[2])) {
       curl_off_t value;
-      const char *p = &line[2] + strlen("OK [UIDVALIDITY ");
+      const char *p = &line[2] + CURL_CSTRLEN("OK [UIDVALIDITY ");
       if(!curlx_str_number(&p, &value, UINT_MAX)) {
         imapc->mb_uidvalidity = (unsigned int)value;
         imapc->mb_uidvalidity_set = TRUE;
diff --git a/lib/ldap.c b/lib/ldap.c
index dac472d4c9..a7c1fe8c83 100644
--- a/lib/ldap.c
+++ b/lib/ldap.c
@@ -976,9 +976,9 @@ void Curl_ldap_version(char *buf, size_t bufsz)
   curl_msnprintf(buf, bufsz, "WinLDAP");
 #else
 #ifdef LDAP_OPT_X_TLS_PASSPHRASE
-  static const char *flavor = "/Apple";
+  static const char flavor[] = "/Apple";
 #else
-  static const char *flavor = "";
+  static const char flavor[] = "";
 #endif
   LDAPAPIInfo api;
   api.ldapai_info_version = LDAP_API_INFO_VERSION;
diff --git a/lib/mqtt.c b/lib/mqtt.c
index a9cdf21498..0858fd65f6 100644
--- a/lib/mqtt.c
+++ b/lib/mqtt.c
@@ -276,7 +276,7 @@ static CURLcode mqtt_connect(struct Curl_easy *data)
   size_t start_user = 0;
   size_t start_pwd = 0;
   char client_id[MQTT_CLIENTID_LEN + 1] = "curl";
-  const size_t clen = strlen("curl");
+  const size_t clen = CURL_CSTRLEN("curl");
   char *packet = NULL;
 
   /* extracting username from request */
@@ -627,7 +627,7 @@ static bool mqtt_decode_len(size_t *lenp, const unsigned char *buf,
 }
 
 #if defined(DEBUGBUILD) && defined(CURLVERBOSE)
-static const char *statenames[] = {
+static const char * const statenames[] = {
   "MQTT_FIRST",
   "MQTT_REMAINING_LENGTH",
   "MQTT_CONNACK",
diff --git a/lib/progress.c b/lib/progress.c
index 3c0f3d57d7..b6322461d5 100644
--- a/lib/progress.c
+++ b/lib/progress.c
@@ -91,7 +91,7 @@ UNITTEST char *max6out(curl_off_t bytes, char *max6, size_t mlen)
   if(bytes < 100000)
     curl_msnprintf(max6, mlen, "%6" CURL_FORMAT_CURL_OFF_T, bytes);
   else {
-    const char unit[] = { 'k', 'M', 'G', 'T', 'P', 'E', 0 };
+    static const char unit[] = { 'k', 'M', 'G', 'T', 'P', 'E', 0 };
     int k = 0;
     curl_off_t nbytes;
     curl_off_t rest;
diff --git a/lib/smb.c b/lib/smb.c
index 2d1a859aa1..4299190ff5 100644
--- a/lib/smb.c
+++ b/lib/smb.c
@@ -654,9 +654,10 @@ static CURLcode smb_send_negotiate(struct Curl_easy *data,
                                    struct smb_conn *smbc,
                                    struct smb_request *req)
 {
-  const char *msg = "\x00\x0c\x00\x02NT LM 0.12";
+  static const char msg[] = "\x00\x0c\x00\x02NT LM 0.12";
 
-  return smb_send_message(data, smbc, req, SMB_COM_NEGOTIATE, msg, 15);
+  return smb_send_message(data, smbc, req, SMB_COM_NEGOTIATE, msg,
+                          sizeof(msg));
 }
 
 static CURLcode smb_send_setup(struct Curl_easy *data)
@@ -678,7 +679,7 @@ static CURLcode smb_send_setup(struct Curl_easy *data)
 
   byte_count = sizeof(lm) + sizeof(nt) +
     strlen(smbc->user) + strlen(smbc->domain) +
-    strlen(CURL_OS) + strlen(CLIENTNAME) + 4; /* 4 null chars */
+    CURL_CSTRLEN(CURL_OS) + CURL_CSTRLEN(CLIENTNAME) + 4; /* 4 null chars */
   if(byte_count > sizeof(msg.bytes))
     return CURLE_FILESIZE_EXCEEDED;
 
@@ -724,7 +725,7 @@ static CURLcode smb_send_tree_connect(struct Curl_easy *data,
   char *p = msg.bytes;
   const size_t byte_count = strlen(conn->origin->hostname) +
     strlen(smbc->share) +
-    strlen(SERVICENAME) + 5; /* 2 nulls and 3 backslashes */
+    CURL_CSTRLEN(SERVICENAME) + 5; /* 2 nulls and 3 backslashes */
 
   if(byte_count > sizeof(msg.bytes))
     return CURLE_FILESIZE_EXCEEDED;
diff --git a/lib/tftp.c b/lib/tftp.c
index d5c85a3100..c101edebed 100644
--- a/lib/tftp.c
+++ b/lib/tftp.c
@@ -278,7 +278,7 @@ static CURLcode tftp_parse_option_ack(struct tftp_conn *state,
 
     infof(data, "got option=(%s) value=(%s)", option, value);
 
-    if((strlen(TFTP_OPTION_BLKSIZE) == olen) &&
+    if((CURL_CSTRLEN(TFTP_OPTION_BLKSIZE) == olen) &&
        checkprefix(TFTP_OPTION_BLKSIZE, option)) {
       curl_off_t blksize;
       if(curlx_str_number(&value, &blksize, TFTP_BLKSIZE_MAX)) {
@@ -308,7 +308,7 @@ static CURLcode tftp_parse_option_ack(struct tftp_conn *state,
       infof(data, "blksize parsed from OACK (%u) requested (%u)",
             state->blksize, state->requested_blksize);
     }
-    else if((strlen(TFTP_OPTION_TSIZE) == olen) &&
+    else if((CURL_CSTRLEN(TFTP_OPTION_TSIZE) == olen) &&
             checkprefix(TFTP_OPTION_TSIZE, option)) {
       curl_off_t tsize = 0;
       /* tsize should be ignored on upload: Who cares about the size of the
diff --git a/lib/vquic/cf-quiche.c b/lib/vquic/cf-quiche.c
index c23b810254..bfc68adf14 100644
--- a/lib/vquic/cf-quiche.c
+++ b/lib/vquic/cf-quiche.c
@@ -1298,9 +1298,8 @@ static CURLcode cf_quiche_ctx_open(struct Curl_cfilter *cf,
     10 * QUIC_MAX_STREAMS * H3_STREAM_WINDOW_SIZE);
   quiche_config_set_max_stream_window(ctx->cfg, 10 * H3_STREAM_WINDOW_SIZE);
   quiche_config_set_application_protos(ctx->cfg,
-                       (uint8_t *)CURL_UNCONST(QUICHE_H3_APPLICATION_PROTOCOL),
-                                       sizeof(QUICHE_H3_APPLICATION_PROTOCOL)
-                                       - 1);
+                      (uint8_t *)CURL_UNCONST(QUICHE_H3_APPLICATION_PROTOCOL),
+                                 CURL_CSTRLEN(QUICHE_H3_APPLICATION_PROTOCOL));
 
   result = Curl_vquic_tls_init(&ctx->tls, cf, data, &ctx->ssl_peer,
                                &ALPN_SPEC_H3, NULL, NULL, cf, NULL);
@@ -1351,7 +1350,7 @@ static CURLcode cf_quiche_ctx_open(struct Curl_cfilter *cf,
     unsigned alpn_len, offset = 0;
 
     /* Replace each ALPN length prefix by a comma. */
-    while(offset < sizeof(alpn_protocols) - 1) {
+    while(offset < CURL_CSTRLEN(alpn_protocols)) {
       alpn_len = alpn_protocols[offset];
       alpn_protocols[offset] = ',';
       offset += 1 + alpn_len;
diff --git a/lib/vssh/libssh2.c b/lib/vssh/libssh2.c
index effcc9beaf..940c678358 100644
--- a/lib/vssh/libssh2.c
+++ b/lib/vssh/libssh2.c
@@ -1768,7 +1768,7 @@ static CURLcode ssh_state_sftp_realpath(struct Curl_easy *data,
     return CURLE_FAILED_INIT;
 
   rc = libssh2_sftp_symlink_ex(sshc->sftp_session, ".",
-                               curlx_uztoui(strlen(".")),
+                               curlx_uztoui(CURL_CSTRLEN(".")),
                                sshp->readdir_filename, CURL_PATH_MAX,
                                LIBSSH2_SFTP_REALPATH);
   if(rc == LIBSSH2_ERROR_EAGAIN)
diff --git a/lib/vtls/cipher_suite.c b/lib/vtls/cipher_suite.c
index 197055fc0d..2c6a0c02d0 100644
--- a/lib/vtls/cipher_suite.c
+++ b/lib/vtls/cipher_suite.c
@@ -48,7 +48,7 @@
 
 /* Text for cipher suite parts (max 64 entries),
    keep indexes below in sync with this! */
-static const char *cs_txt =
+static const char cs_txt[] =
   "\0"
   "TLS" "\0"
   "WITH" "\0"
diff --git a/lib/vtls/gtls.c b/lib/vtls/gtls.c
index 423179172f..92607b1135 100644
--- a/lib/vtls/gtls.c
+++ b/lib/vtls/gtls.c
@@ -591,7 +591,7 @@ static struct gtls_shared_creds *gtls_get_cached_creds(struct Curl_cfilter *cf,
   if(data->multi) {
     shared_creds = Curl_hash_pick(&data->multi->proto_hash,
                                   CURL_UNCONST(MPROTO_GTLS_X509_KEY),
-                                  sizeof(MPROTO_GTLS_X509_KEY) - 1);
+                                  CURL_CSTRLEN(MPROTO_GTLS_X509_KEY));
     if(shared_creds && shared_creds->creds &&
        !gtls_shared_creds_expired(data, shared_creds) &&
        !gtls_shared_creds_different(cf, shared_creds)) {
@@ -604,7 +604,7 @@ static struct gtls_shared_creds *gtls_get_cached_creds(struct Curl_cfilter *cf,
 static void gtls_shared_creds_hash_free(void *key, size_t key_len, void *p)
 {
   struct gtls_shared_creds *sc = p;
-  DEBUGASSERT(key_len == (sizeof(MPROTO_GTLS_X509_KEY) - 1));
+  DEBUGASSERT(key_len == CURL_CSTRLEN(MPROTO_GTLS_X509_KEY));
   DEBUGASSERT(!memcmp(MPROTO_GTLS_X509_KEY, key, key_len));
   (void)key;
   (void)key_len;
@@ -635,7 +635,7 @@ static void gtls_set_cached_creds(struct Curl_cfilter *cf,
 
   if(!Curl_hash_add2(&data->multi->proto_hash,
                      CURL_UNCONST(MPROTO_GTLS_X509_KEY),
-                     sizeof(MPROTO_GTLS_X509_KEY) - 1,
+                     CURL_CSTRLEN(MPROTO_GTLS_X509_KEY),
                      sc, gtls_shared_creds_hash_free)) {
     Curl_gtls_shared_creds_free(&sc); /* down reference again */
     return;
diff --git a/lib/vtls/keylog.h b/lib/vtls/keylog.h
index b09fcc6f4d..f95dfeae2d 100644
--- a/lib/vtls/keylog.h
+++ b/lib/vtls/keylog.h
@@ -25,7 +25,7 @@
  ***************************************************************************/
 #include "curl_setup.h"
 
-#define KEYLOG_LABEL_MAXLEN (sizeof("CLIENT_HANDSHAKE_TRAFFIC_SECRET") - 1)
+#define KEYLOG_LABEL_MAXLEN CURL_CSTRLEN("CLIENT_HANDSHAKE_TRAFFIC_SECRET")
 
 #define CLIENT_RANDOM_SIZE  32
 
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 9f576a9d52..12903038f1 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -248,7 +248,7 @@ static CURLcode X509V3_ext(struct Curl_easy *data,
 
     if(asn1_object_dump(obj, namebuf, sizeof(namebuf)))
       /* make sure the name is null-terminated */
-      namebuf[sizeof(namebuf) - 1] = 0;
+      namebuf[CURL_CSTRLEN(namebuf)] = 0;
 
     if(!X509V3_EXT_print(bio_out, ext, 0, 0))
       ASN1_STRING_print(bio_out,
@@ -1176,7 +1176,7 @@ static int engineload(struct Curl_easy *data,
   }
 
   if(data->state.engine) {
-    const char *cmd_name = "LOAD_CERT_CTRL";
+    static const char cmd_name[] = "LOAD_CERT_CTRL";
     struct {
       const char *cert_id;
       X509 *cert;
@@ -2965,7 +2965,7 @@ static CURLcode ossl_windows_load_anchors(struct Curl_cfilter *cf,
      https://stackoverflow.com/questions/9507184/
      https://github.com/d3x0r/SACK/blob/ff15424d3c581b86d40f818532e5a400c516d39d/src/netlib/ssl_layer.c#L1410
      https://datatracker.ietf.org/doc/html/rfc5280 */
-  const char *win_stores[] = {
+  static const char * const win_stores[] = {
     "ROOT",   /* Trusted Root Certification Authorities */
     "CA"      /* Intermediate Certification Authorities */
   };
@@ -3180,7 +3180,7 @@ struct ossl_x509_share {
 static void oss_x509_share_free(void *key, size_t key_len, void *p)
 {
   struct ossl_x509_share *share = p;
-  DEBUGASSERT(key_len == (sizeof(MPROTO_OSSL_X509_KEY) - 1));
+  DEBUGASSERT(key_len == CURL_CSTRLEN(MPROTO_OSSL_X509_KEY));
   DEBUGASSERT(!memcmp(MPROTO_OSSL_X509_KEY, key, key_len));
   (void)key;
   (void)key_len;
@@ -3231,7 +3231,7 @@ static X509_STORE *ossl_get_cached_x509_store(struct Curl_cfilter *cf,
   *pempty = TRUE;
   share = multi ? Curl_hash_pick(&multi->proto_hash,
                                  CURL_UNCONST(MPROTO_OSSL_X509_KEY),
-                                 sizeof(MPROTO_OSSL_X509_KEY) - 1) : NULL;
+                                 CURL_CSTRLEN(MPROTO_OSSL_X509_KEY)) : NULL;
   if(share && share->store &&
      !ossl_cached_x509_store_expired(data, share) &&
      !ossl_cached_x509_store_different(cf, data, share)) {
@@ -3256,7 +3256,7 @@ static void ossl_set_cached_x509_store(struct Curl_cfilter *cf,
     return;
   share = Curl_hash_pick(&multi->proto_hash,
                          CURL_UNCONST(MPROTO_OSSL_X509_KEY),
-                         sizeof(MPROTO_OSSL_X509_KEY) - 1);
+                         CURL_CSTRLEN(MPROTO_OSSL_X509_KEY));
 
   if(!share) {
     share = curlx_calloc(1, sizeof(*share));
@@ -3264,7 +3264,7 @@ static void ossl_set_cached_x509_store(struct Curl_cfilter *cf,
       return;
     if(!Curl_hash_add2(&multi->proto_hash,
                        CURL_UNCONST(MPROTO_OSSL_X509_KEY),
-                       sizeof(MPROTO_OSSL_X509_KEY) - 1,
+                       CURL_CSTRLEN(MPROTO_OSSL_X509_KEY),
                        share, oss_x509_share_free)) {
       curlx_free(share);
       return;
@@ -5283,7 +5283,7 @@ static CURLcode ossl_get_channel_binding(struct Curl_easy *data,
   unsigned int length;
   unsigned char buf[EVP_MAX_MD_SIZE];
 
-  const char prefix[] = "tls-server-end-point:";
+  static const char prefix[] = "tls-server-end-point:";
   struct connectdata *conn = data->conn;
   struct Curl_cfilter *cf = conn->cfilter[sockindex];
   struct ossl_ctx *octx = NULL;
@@ -5405,7 +5405,7 @@ static CURLcode ossl_get_channel_binding(struct Curl_easy *data,
   }
 
   /* Append "tls-server-end-point:" */
-  result = curlx_dyn_addn(binding, prefix, sizeof(prefix) - 1);
+  result = curlx_dyn_addn(binding, prefix, CURL_CSTRLEN(prefix));
   if(result)
     goto out;
 
@@ -5423,9 +5423,9 @@ size_t Curl_ossl_version(char *buffer, size_t size)
   char *p;
   size_t count;
   const char *ver = OpenSSL_version(OPENSSL_VERSION);
-  const char expected[] = OSSL_PACKAGE " "; /* ie "LibreSSL " */
-  if(curl_strnequal(ver, expected, sizeof(expected) - 1)) {
-    ver += sizeof(expected) - 1;
+  static const char expected[] = OSSL_PACKAGE " "; /* ie "LibreSSL " */
+  if(curl_strnequal(ver, expected, CURL_CSTRLEN(expected))) {
+    ver += CURL_CSTRLEN(expected);
   }
   count = curl_msnprintf(buffer, size, "%s/%s", OSSL_PACKAGE, ver);
   for(p = buffer; *p; ++p) {
diff --git a/lib/vtls/schannel.c b/lib/vtls/schannel.c
index 17c1c8d195..f55784c624 100644
--- a/lib/vtls/schannel.c
+++ b/lib/vtls/schannel.c
@@ -291,9 +291,9 @@ static CURLcode set_ssl_ciphers(SCHANNEL_CRED *schannel_cred, char *ciphers,
     if(alg)
       algIds[algCount++] = (ALG_ID)alg;
     else if(!strncmp(startCur, "USE_STRONG_CRYPTO",
-                     sizeof("USE_STRONG_CRYPTO") - 1) ||
+                     CURL_CSTRLEN("USE_STRONG_CRYPTO")) ||
             !strncmp(startCur, "SCH_USE_STRONG_CRYPTO",
-                     sizeof("SCH_USE_STRONG_CRYPTO") - 1))
+                     CURL_CSTRLEN("SCH_USE_STRONG_CRYPTO")))
       schannel_cred->dwFlags |= SCH_USE_STRONG_CRYPTO;
     else
       return CURLE_SSL_CIPHER;
@@ -2736,7 +2736,7 @@ HCERTSTORE Curl_schannel_get_cached_cert_store(struct Curl_cfilter *cf,
 
   share = Curl_hash_pick(&multi->proto_hash,
                          CURL_UNCONST(MPROTO_SCHANNEL_CERT_SHARE_KEY),
-                         sizeof(MPROTO_SCHANNEL_CERT_SHARE_KEY) - 1);
+                         CURL_CSTRLEN(MPROTO_SCHANNEL_CERT_SHARE_KEY));
   if(!share || !share->cert_store) {
     return NULL;
   }
@@ -2785,7 +2785,7 @@ HCERTSTORE Curl_schannel_get_cached_cert_store(struct Curl_cfilter *cf,
 static void schannel_cert_share_free(void *key, size_t key_len, void *p)
 {
   struct schannel_cert_share *share = p;
-  DEBUGASSERT(key_len == (sizeof(MPROTO_SCHANNEL_CERT_SHARE_KEY) - 1));
+  DEBUGASSERT(key_len == CURL_CSTRLEN(MPROTO_SCHANNEL_CERT_SHARE_KEY));
   DEBUGASSERT(!memcmp(MPROTO_SCHANNEL_CERT_SHARE_KEY, key, key_len));
   (void)key;
   (void)key_len;
@@ -2828,7 +2828,7 @@ bool Curl_schannel_set_cached_cert_store(struct Curl_cfilter *cf,
 
   share = Curl_hash_pick(&multi->proto_hash,
                          CURL_UNCONST(MPROTO_SCHANNEL_CERT_SHARE_KEY),
-                         sizeof(MPROTO_SCHANNEL_CERT_SHARE_KEY) - 1);
+                         CURL_CSTRLEN(MPROTO_SCHANNEL_CERT_SHARE_KEY));
   if(!share) {
     share = curlx_calloc(1, sizeof(*share));
     if(!share) {
@@ -2837,7 +2837,7 @@ bool Curl_schannel_set_cached_cert_store(struct Curl_cfilter *cf,
     }
     if(!Curl_hash_add2(&multi->proto_hash,
                        CURL_UNCONST(MPROTO_SCHANNEL_CERT_SHARE_KEY),
-                       sizeof(MPROTO_SCHANNEL_CERT_SHARE_KEY) - 1,
+                       CURL_CSTRLEN(MPROTO_SCHANNEL_CERT_SHARE_KEY),
                        share, schannel_cert_share_free)) {
       curlx_free(share);
       curlx_free(CAfile);
diff --git a/lib/vtls/schannel_verify.c b/lib/vtls/schannel_verify.c
index e5fe2249a6..6e55c9b839 100644
--- a/lib/vtls/schannel_verify.c
+++ b/lib/vtls/schannel_verify.c
@@ -119,8 +119,8 @@ static CURLcode add_certs_data_to_store(HCERTSTORE trust_store,
                                         const char *ca_file_text,
                                         struct Curl_easy *data)
 {
-  const size_t begin_cert_len = strlen(BEGIN_CERT);
-  const size_t end_cert_len = strlen(END_CERT);
+  const size_t begin_cert_len = CURL_CSTRLEN(BEGIN_CERT);
+  const size_t end_cert_len = CURL_CSTRLEN(END_CERT);
   CURLcode result = CURLE_OK;
   int num_certs = 0;
   bool more_certs = 1;
diff --git a/lib/vtls/vtls.c b/lib/vtls/vtls.c
index 2da004adba..952c5e5e71 100644
--- a/lib/vtls/vtls.c
+++ b/lib/vtls/vtls.c
@@ -483,8 +483,8 @@ CURLcode Curl_pin_peer_pubkey(struct Curl_easy *data,
 
     pinned_hash = pinnedpubkey;
     while(pinned_hash &&
-          !strncmp(pinned_hash, "sha256//", (sizeof("sha256//") - 1))) {
-      pinned_hash = pinned_hash + (sizeof("sha256//") - 1);
+          !strncmp(pinned_hash, "sha256//", CURL_CSTRLEN("sha256//"))) {
+      pinned_hash = pinned_hash + CURL_CSTRLEN("sha256//");
       end_pos = strchr(pinned_hash, ';');
       pinned_hash_len = end_pos ?
                         (size_t)(end_pos - pinned_hash) : strlen(pinned_hash);
diff --git a/lib/vtls/wolfssl.c b/lib/vtls/wolfssl.c
index e6ee960117..9fe0dc1c88 100644
--- a/lib/vtls/wolfssl.c
+++ b/lib/vtls/wolfssl.c
@@ -686,7 +686,7 @@ struct wssl_x509_share {
 static void wssl_x509_share_free(void *key, size_t key_len, void *p)
 {
   struct wssl_x509_share *share = p;
-  DEBUGASSERT(key_len == (sizeof(MPROTO_WSSL_X509_KEY) - 1));
+  DEBUGASSERT(key_len == CURL_CSTRLEN(MPROTO_WSSL_X509_KEY));
   DEBUGASSERT(!memcmp(MPROTO_WSSL_X509_KEY, key, key_len));
   (void)key;
   (void)key_len;
@@ -730,7 +730,7 @@ static WOLFSSL_X509_STORE *wssl_get_cached_x509_store(struct Curl_cfilter *cf,
   DEBUGASSERT(multi);
   share = multi ? Curl_hash_pick(&multi->proto_hash,
                                  CURL_UNCONST(MPROTO_WSSL_X509_KEY),
-                                 sizeof(MPROTO_WSSL_X509_KEY) - 1) : NULL;
+                                 CURL_CSTRLEN(MPROTO_WSSL_X509_KEY)) : NULL;
   if(share && share->store &&
      !wssl_cached_x509_store_expired(data, share) &&
      !wssl_cached_x509_store_different(cf, share)) {
@@ -753,7 +753,7 @@ static void wssl_set_cached_x509_store(struct Curl_cfilter *cf,
     return;
   share = Curl_hash_pick(&multi->proto_hash,
                          CURL_UNCONST(MPROTO_WSSL_X509_KEY),
-                         sizeof(MPROTO_WSSL_X509_KEY) - 1);
+                         CURL_CSTRLEN(MPROTO_WSSL_X509_KEY));
 
   if(!share) {
     share = curlx_calloc(1, sizeof(*share));
@@ -761,7 +761,7 @@ static void wssl_set_cached_x509_store(struct Curl_cfilter *cf,
       return;
     if(!Curl_hash_add2(&multi->proto_hash,
                        CURL_UNCONST(MPROTO_WSSL_X509_KEY),
-                       sizeof(MPROTO_WSSL_X509_KEY) - 1,
+                       CURL_CSTRLEN(MPROTO_WSSL_X509_KEY),
                        share, wssl_x509_share_free)) {
       curlx_free(share);
       return;
diff --git a/scripts/schemetable.c b/scripts/schemetable.c
index 8127ecd2a1..67f6b81b14 100644
--- a/scripts/schemetable.c
+++ b/scripts/schemetable.c
@@ -29,7 +29,7 @@
  * function in url.c.
  */
 
-static const char *scheme[] = {
+static const char * const scheme[] = {
   "dict",
   "file",
   "ftp",
diff --git a/src/curlinfo.c b/src/curlinfo.c
index 36eabeb78f..8b4659200f 100644
--- a/src/curlinfo.c
+++ b/src/curlinfo.c
@@ -43,7 +43,7 @@
 #include <openssl/opensslconf.h> /* for OPENSSL_NO_OCSP */
 #endif
 
-static const char *disabled[] = {
+static const char * const disabled[] = {
   "bindlocal: "
 #ifdef CURL_DISABLE_BINDLOCAL
   "OFF"
diff --git a/src/tool_doswin.c b/src/tool_doswin.c
index a64665bcd9..52eb69bd69 100644
--- a/src/tool_doswin.c
+++ b/src/tool_doswin.c
@@ -145,13 +145,13 @@ static SANITIZEcode msdosify(char ** const sanitized, const char *file_name,
   static const char illegal_chars_dos[] =
     ".+, ;=[]"     /* illegal in DOS */
     "|<>/\\\":?*"; /* illegal in DOS & W95 */
-  static const char *illegal_chars_w95 = &illegal_chars_dos[8];
+  static const char * const illegal_chars_w95 = &illegal_chars_dos[8];
   int idx, dot_idx;
   const char *s = file_name;
   char *d = dos_name;
-  const char * const dlimit = dos_name + sizeof(dos_name) - 1;
+  const char * const dlimit = dos_name + CURL_CSTRLEN(dos_name);
   const char *illegal_aliens = illegal_chars_dos;
-  size_t len = sizeof(illegal_chars_dos) - 1;
+  size_t len = CURL_CSTRLEN(illegal_chars_dos);
 
   if(!sanitized)
     return SANITIZE_ERR_BAD_ARGUMENT;
diff --git a/src/tool_easysrc.c b/src/tool_easysrc.c
index 5b3c6cb45b..c2a34c3b2b 100644
--- a/src/tool_easysrc.c
+++ b/src/tool_easysrc.c
@@ -64,7 +64,7 @@ static const char * const srchard[] = {
   "",
   NULL
 };
-static const char *const srcend[] = {
+static const char * const srcend[] = {
   "",
   "  return (int)result;",
   "}",
diff --git a/src/tool_formparse.c b/src/tool_formparse.c
index 6d41711a40..450a2b3a99 100644
--- a/src/tool_formparse.c
+++ b/src/tool_formparse.c
@@ -509,7 +509,7 @@ static void param_type(char **ptr, char **ptype, char **endct, char *sep)
 {
   char *p = *ptr;
   size_t tlen;
-  for(p += sizeof("type=") - 1; ISBLANK(*p); p++)
+  for(p += CURL_CSTRLEN("type="); ISBLANK(*p); p++)
     ;
   /* set type pointer */
   *ptype = p;
@@ -533,7 +533,7 @@ static void param_filename(char **ptr, char **endct, char **pfilename,
     **endct = '\0';
     *endct = NULL;
   }
-  for(p += sizeof("filename=") - 1; ISBLANK(*p); p++)
+  for(p += CURL_CSTRLEN("filename="); ISBLANK(*p); p++)
     ;
   tp = p;
   *pfilename = get_param_word(&p, &endpos, endchar);
@@ -557,7 +557,7 @@ static int param_headers(char **ptr, char **endct,
     **endct = '\0';
     *endct = NULL;
   }
-  p += sizeof("headers=") - 1;
+  p += CURL_CSTRLEN("headers=");
   if(*p == '@' || *p == '<') {
     char *hdrfile;
     FILE *fp;
@@ -623,7 +623,7 @@ static void param_encoder(char **ptr, char **endct, char **pencoder,
     **endct = '\0';
     *endct = NULL;
   }
-  for(p += sizeof("encoder=") - 1; ISBLANK(*p); p++)
+  for(p += CURL_CSTRLEN("encoder="); ISBLANK(*p); p++)
     ;
   tp = p;
   *pencoder = get_param_word(&p, &endpos, endchar);
diff --git a/src/tool_getparam.c b/src/tool_getparam.c
index 479168e0bd..73419ead09 100644
--- a/src/tool_getparam.c
+++ b/src/tool_getparam.c
@@ -2488,7 +2488,7 @@ static ParameterError opt_string(struct OperationConfig *config,
 {
   ParameterError err = PARAM_OK;
   curl_off_t value;
-  static const char *redir_protos[] = {
+  static const char * const redir_protos[] = {
     "http",
     "https",
     "ftp",
diff --git a/src/tool_helpers.c b/src/tool_helpers.c
index b5e9b54121..1b998d2ca6 100644
--- a/src/tool_helpers.c
+++ b/src/tool_helpers.c
@@ -77,7 +77,7 @@ const char *param2text(ParameterError error)
 int SetHTTPrequest(HttpReq req, HttpReq *store)
 {
   /* this mirrors the HttpReq enum in tool_sdecls.h */
-  const char *reqname[] = {
+  static const char * const reqname[] = {
     "", /* unspec */
     "GET (-G, --get)",
     "HEAD (-I, --head)",
@@ -101,7 +101,7 @@ int SetHTTPrequest(HttpReq req, HttpReq *store)
 void customrequest_helper(HttpReq req, const char *method)
 {
   /* this mirrors the HttpReq enum in tool_sdecls.h */
-  const char *dflt[] = {
+  static const char * const dflt[] = {
     "GET",
     "GET",
     "HEAD",
diff --git a/src/tool_libinfo.c b/src/tool_libinfo.c
index bce6bb7d6e..dfb23912f3 100644
--- a/src/tool_libinfo.c
+++ b/src/tool_libinfo.c
@@ -27,7 +27,7 @@
 
 /* global variable definitions, for libcurl runtime info */
 
-static const char *no_protos = NULL;
+static const char * const no_protos = NULL;
 
 curl_version_info_data *curlinfo = NULL;
 const char * const *built_in_protos = &no_protos;
diff --git a/src/tool_paramhlp.c b/src/tool_paramhlp.c
index 57a49ef97f..a3be2afcf7 100644
--- a/src/tool_paramhlp.c
+++ b/src/tool_paramhlp.c
@@ -297,7 +297,7 @@ ParameterError secs2ms(long *val, const char *str)
 {
   curl_off_t secs;
   long ms = 0;
-  const unsigned int digs[] = {
+  static const unsigned int digs[] = {
     1,
     10,
     100,
diff --git a/src/tool_progress.c b/src/tool_progress.c
index c30644c0e3..d3ee694fea 100644
--- a/src/tool_progress.c
+++ b/src/tool_progress.c
@@ -35,7 +35,7 @@
 UNITTEST char *max5data(curl_off_t bytes, char *max5, size_t mlen)
 {
   /* a signed 64-bit value is 8192 petabytes maximum */
-  const char unit[] = { 'k', 'M', 'G', 'T', 'P', 'E', 0 };
+  static const char unit[] = { 'k', 'M', 'G', 'T', 'P', 'E', 0 };
   int k = 0;
   if(bytes < 100000) {
     curl_msnprintf(max5, mlen, "%5" CURL_FORMAT_CURL_OFF_T, bytes);
diff --git a/src/var.c b/src/var.c
index 8f9dbbb5b0..464b0c1c2c 100644
--- a/src/var.c
+++ b/src/var.c
@@ -62,15 +62,15 @@ static const struct tool_var *varcontent(const char *name, size_t nlen)
   (!strncmp(ptr, name, len) && ENDOFFUNC((ptr)[len]))
 
 #define FUNC_TRIM      "trim"
-#define FUNC_TRIM_LEN  (sizeof(FUNC_TRIM) - 1)
+#define FUNC_TRIM_LEN  CURL_CSTRLEN(FUNC_TRIM)
 #define FUNC_JSON      "json"
-#define FUNC_JSON_LEN  (sizeof(FUNC_JSON) - 1)
+#define FUNC_JSON_LEN  CURL_CSTRLEN(FUNC_JSON)
 #define FUNC_URL       "url"
-#define FUNC_URL_LEN   (sizeof(FUNC_URL) - 1)
+#define FUNC_URL_LEN   CURL_CSTRLEN(FUNC_URL)
 #define FUNC_B64       "b64"
-#define FUNC_B64_LEN   (sizeof(FUNC_B64) - 1)
+#define FUNC_B64_LEN   CURL_CSTRLEN(FUNC_B64)
 #define FUNC_64DEC     "64dec" /* base64 decode */
-#define FUNC_64DEC_LEN (sizeof(FUNC_64DEC) - 1)
+#define FUNC_64DEC_LEN CURL_CSTRLEN(FUNC_64DEC)
 
 static ParameterError varfunc(char *c, /* content */
                               size_t clen, /* content length */
diff --git a/tests/http/testenv/mod_curltest/mod_curltest.c b/tests/http/testenv/mod_curltest/mod_curltest.c
index 0bb0c78a36..d783af1ab6 100644
--- a/tests/http/testenv/mod_curltest/mod_curltest.c
+++ b/tests/http/testenv/mod_curltest/mod_curltest.c
@@ -949,7 +949,7 @@ static int curltest_post_config(apr_pool_t *p, apr_pool_t *plog,
                                 apr_pool_t *ptemp, server_rec *s)
 {
   void *data = NULL;
-  const char *key = "mod_curltest_init_counter";
+  static const char *key = "mod_curltest_init_counter";
 
   (void)p;
   (void)plog;
diff --git a/tests/libtest/lib1514.c b/tests/libtest/lib1514.c
index a799e7668d..528468eee0 100644
--- a/tests/libtest/lib1514.c
+++ b/tests/libtest/lib1514.c
@@ -29,7 +29,7 @@
 #include "first.h"
 
 struct t1514_WriteThis {
-  char *readptr;
+  const char *readptr;
   size_t sizeleft;
 };
 
@@ -55,9 +55,9 @@ static CURLcode test_lib1514(const char *URL)
   CURL *curl;
   CURLcode result = CURLE_OK;
 
-  static char testdata[] = "dummy";
+  static const char testdata[] = "dummy";
 
-  struct t1514_WriteThis pooh = { testdata, sizeof(testdata) - 1 };
+  struct t1514_WriteThis pooh = { testdata, CURL_CSTRLEN(testdata) };
 
   global_init(CURL_GLOBAL_ALL);
 
diff --git a/tests/libtest/lib1517.c b/tests/libtest/lib1517.c
index 30e80a7bce..a88705ed68 100644
--- a/tests/libtest/lib1517.c
+++ b/tests/libtest/lib1517.c
@@ -60,7 +60,7 @@ static CURLcode test_lib1517(const char *URL)
   struct t1517_WriteThis pooh;
 
   pooh.readptr = testdata;
-  pooh.sizeleft = sizeof(testdata) - 1;
+  pooh.sizeleft = CURL_CSTRLEN(testdata);
 
   if(curl_global_init(CURL_GLOBAL_ALL)) {
     curl_mfprintf(stderr, "curl_global_init() failed\n");
diff --git a/tests/libtest/lib1520.c b/tests/libtest/lib1520.c
index 9ed257591e..b97fd94fc8 100644
--- a/tests/libtest/lib1520.c
+++ b/tests/libtest/lib1520.c
@@ -29,7 +29,7 @@ struct upload_status {
 
 static size_t t1520_read_cb(char *ptr, size_t size, size_t nmemb, void *userp)
 {
-  static const char *payload_text[] = {
+  static const char * const payload_text[] = {
     "From: different\r\n",
     "To: another\r\n",
     "\r\n",
diff --git a/tests/libtest/lib1525.c b/tests/libtest/lib1525.c
index 3498941ea2..7465eb59dd 100644
--- a/tests/libtest/lib1525.c
+++ b/tests/libtest/lib1525.c
@@ -31,7 +31,7 @@
 #include "first.h"
 
 static const char t1525_data[] = "Hello Cloud!\n";
-static size_t const t1525_datalen = sizeof(t1525_data) - 1;
+static const size_t t1525_datalen = CURL_CSTRLEN(t1525_data);
 
 static size_t t1525_read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 {
diff --git a/tests/libtest/lib1526.c b/tests/libtest/lib1526.c
index 6e01804628..56b1b749b3 100644
--- a/tests/libtest/lib1526.c
+++ b/tests/libtest/lib1526.c
@@ -30,7 +30,7 @@
 #include "first.h"
 
 static const char t1526_data[] = "Hello Cloud!\n";
-static size_t const t1526_datalen = sizeof(t1526_data) - 1;
+static const size_t t1526_datalen = CURL_CSTRLEN(t1526_data);
 
 static size_t t1526_read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 {
diff --git a/tests/libtest/lib1527.c b/tests/libtest/lib1527.c
index ef438dc901..1caa37d8d3 100644
--- a/tests/libtest/lib1527.c
+++ b/tests/libtest/lib1527.c
@@ -30,7 +30,7 @@
 #include "first.h"
 
 static const char t1527_data[] = "Hello Cloud!\n";
-static size_t const t1527_datalen = sizeof(t1527_data) - 1;
+static const size_t t1527_datalen = CURL_CSTRLEN(t1527_data);
 
 static size_t t1527_read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 {
diff --git a/tests/libtest/lib1531.c b/tests/libtest/lib1531.c
index def737f9f1..20ac3639eb 100644
--- a/tests/libtest/lib1531.c
+++ b/tests/libtest/lib1531.c
@@ -25,8 +25,8 @@
 
 static CURLcode test_lib1531(const char *URL)
 {
-  static char const testdata[] = ".abc\0xyz";
-  static curl_off_t const testdatalen = sizeof(testdata) - 1;
+  static const char testdata[] = ".abc\0xyz";
+  static const curl_off_t testdatalen = CURL_CSTRLEN(testdata);
 
   CURL *curl;
   CURLM *multi;
diff --git a/tests/libtest/lib1537.c b/tests/libtest/lib1537.c
index 1ef0be9c75..7fd91f9d4f 100644
--- a/tests/libtest/lib1537.c
+++ b/tests/libtest/lib1537.c
@@ -25,8 +25,10 @@
 
 static CURLcode test_lib1537(const char *URL)
 {
-  const unsigned char a[] = { 0x2f, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
-                              0x91, 0xa2, 0xb3, 0xc4, 0xd5, 0xe6, 0xf7 };
+  static const unsigned char a[] = {
+    0x2f, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+    0x91, 0xa2, 0xb3, 0xc4, 0xd5, 0xe6, 0xf7
+  };
   CURLcode result = CURLE_OK;
   char *ptr = NULL;
   int asize;
diff --git a/tests/libtest/lib1554.c b/tests/libtest/lib1554.c
index 8b37374c5a..c553095c61 100644
--- a/tests/libtest/lib1554.c
+++ b/tests/libtest/lib1554.c
@@ -23,7 +23,7 @@
  ***************************************************************************/
 #include "first.h"
 
-static const char *ldata_names[] = {
+static const char * const ldata_names[] = {
   "NONE",
   "SHARE",
   "COOKIE",
diff --git a/tests/libtest/lib1560.c b/tests/libtest/lib1560.c
index 1c8aabfd5b..fafdd8de99 100644
--- a/tests/libtest/lib1560.c
+++ b/tests/libtest/lib1560.c
@@ -2269,7 +2269,7 @@ static char bigpart[120000];
  */
 static int huge(void)
 {
-  static const char *smallpart = "c";
+  static const char smallpart[] = "c";
   int i;
   CURLU *urlp = curl_url();
   CURLUcode rc;
@@ -2323,7 +2323,7 @@ static int huge(void)
 
 static int urldup(void)
 {
-  static const char *url[] = {
+  static const char * const url[] = {
     "http://"
     "user:pwd@"
     "[2a04:4e42:e00::347%25eth0]"
diff --git a/tests/libtest/lib1576.c b/tests/libtest/lib1576.c
index 64aaa4c5ea..a052519a25 100644
--- a/tests/libtest/lib1576.c
+++ b/tests/libtest/lib1576.c
@@ -23,8 +23,9 @@
  ***************************************************************************/
 #include "first.h"
 
-static char t1576_data[] = "request indicates that the client, which made";
-static size_t const t1576_datalen = sizeof(t1576_data) - 1;
+static const char t1576_data[] = "request indicates that the client, "
+                                 "which made";
+static const size_t t1576_datalen = CURL_CSTRLEN(t1576_data);
 
 static size_t t1576_read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 {
diff --git a/tests/libtest/lib1591.c b/tests/libtest/lib1591.c
index 97b234234f..427f966564 100644
--- a/tests/libtest/lib1591.c
+++ b/tests/libtest/lib1591.c
@@ -34,7 +34,7 @@ static size_t consumed = 0;
 static size_t t1591_read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 {
   static const char testdata[] = "Hello Cloud!\r\n";
-  static size_t const datalen = sizeof(testdata) - 1;
+  static const size_t datalen = CURL_CSTRLEN(testdata);
 
   size_t amount = nmemb * size; /* Total bytes curl wants */
 
diff --git a/tests/libtest/lib1598.c b/tests/libtest/lib1598.c
index 961c424e68..106a339c07 100644
--- a/tests/libtest/lib1598.c
+++ b/tests/libtest/lib1598.c
@@ -52,7 +52,7 @@ static int t1598_trailers_callback(struct curl_slist **list, void *userdata)
 
 static CURLcode test_lib1598(const char *URL)
 {
-  static const char *post_data = "xxx=yyy&aaa=bbbbb";
+  static const char post_data[] = "xxx=yyy&aaa=bbbbb";
 
   CURL *curl = NULL;
   CURLcode result = CURLE_FAILED_INIT;
@@ -84,7 +84,7 @@ static CURLcode test_lib1598(const char *URL)
 
   easy_setopt(curl, CURLOPT_URL, URL);
   easy_setopt(curl, CURLOPT_HTTPHEADER, hhl);
-  easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)strlen(post_data));
+  easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)CURL_CSTRLEN(post_data));
   easy_setopt(curl, CURLOPT_POSTFIELDS, post_data);
   easy_setopt(curl, CURLOPT_TRAILERFUNCTION, t1598_trailers_callback);
   easy_setopt(curl, CURLOPT_TRAILERDATA, NULL);
diff --git a/tests/libtest/lib1662.c b/tests/libtest/lib1662.c
index 0e4942e9ad..4c338d2921 100644
--- a/tests/libtest/lib1662.c
+++ b/tests/libtest/lib1662.c
@@ -30,7 +30,7 @@ struct t1662_WriteThis {
 static size_t t1662_read_cb(char *ptr, size_t size, size_t nmemb, void *userp)
 {
   static const char testdata[] = "mooaaa";
-  static size_t const testdatalen = sizeof(testdata) - 1;
+  static const size_t testdatalen = CURL_CSTRLEN(testdata);
 
   struct t1662_WriteThis *pooh = (struct t1662_WriteThis *)userp;
 
diff --git a/tests/libtest/lib1901.c b/tests/libtest/lib1901.c
index a6ccbdb0cb..dae52a7f2c 100644
--- a/tests/libtest/lib1901.c
+++ b/tests/libtest/lib1901.c
@@ -25,7 +25,7 @@
 
 static size_t t1901_read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
 {
-  static const char *chunks[] = { "one", "two", "three", "four", NULL };
+  static const char * const chunks[] = { "one", "two", "three", "four", NULL };
   static int ix = 0;
   (void)stream;
   if(chunks[ix]) {
diff --git a/tests/libtest/lib1940.c b/tests/libtest/lib1940.c
index 349d8131c6..a0fea9264f 100644
--- a/tests/libtest/lib1940.c
+++ b/tests/libtest/lib1940.c
@@ -25,7 +25,7 @@
 
 static void t1940_showem(CURL *curl, int header_request, unsigned int type)
 {
-  static const char *testdata[] = {
+  static const char * const testdata[] = {
     "daTE",
     "Server",
     "content-type",
diff --git a/tests/libtest/lib1948.c b/tests/libtest/lib1948.c
index 9b8217be8f..73bd5d7ba0 100644
--- a/tests/libtest/lib1948.c
+++ b/tests/libtest/lib1948.c
@@ -55,9 +55,9 @@ static CURLcode test_lib1948(const char *URL)
   easy_setopt(curl, CURLOPT_HEADER, 1L);
   easy_setopt(curl, CURLOPT_READFUNCTION, put_callback);
   pbuf.buf = testput;
-  pbuf.len = sizeof(testput) - 1;
+  pbuf.len = CURL_CSTRLEN(testput);
   easy_setopt(curl, CURLOPT_READDATA, &pbuf);
-  easy_setopt(curl, CURLOPT_INFILESIZE, (long)(sizeof(testput) - 1));
+  easy_setopt(curl, CURLOPT_INFILESIZE, (long)CURL_CSTRLEN(testput));
   easy_setopt(curl, CURLOPT_URL, URL);
   result = curl_easy_perform(curl);
   if(result)
@@ -66,7 +66,7 @@ static CURLcode test_lib1948(const char *URL)
   /* POST */
   easy_setopt(curl, CURLOPT_POST, 1L);
   easy_setopt(curl, CURLOPT_POSTFIELDS, testput);
-  easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)(sizeof(testput) - 1));
+  easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)CURL_CSTRLEN(testput));
   result = curl_easy_perform(curl);
 
 test_cleanup:
diff --git a/tests/libtest/lib1965.c b/tests/libtest/lib1965.c
index e09ff349b3..683e5a716a 100644
--- a/tests/libtest/lib1965.c
+++ b/tests/libtest/lib1965.c
@@ -27,7 +27,7 @@ static CURLcode test_lib1965(const char *URL)
 {
   CURLcode result = CURLE_OK;
   CURLUcode rc;
-  static const char *schemes[] = {
+  static const char * const schemes[] = {
     "bad!", "bad{", "bad/", "bad\\", "a!",
     "a+123", "http-2", "http.1",
     "a+-.123", "http-+++2", "http.1--",
diff --git a/tests/libtest/lib3102.c b/tests/libtest/lib3102.c
index 59db9e45f1..312d5e600e 100644
--- a/tests/libtest/lib3102.c
+++ b/tests/libtest/lib3102.c
@@ -47,11 +47,11 @@ static bool is_chain_in_order(struct curl_certinfo *cert_info)
       static const char issuer_prefix[] = "Issuer:";
       static const char subject_prefix[] = "Subject:";
 
-      if(!strncmp(slist->data, issuer_prefix, sizeof(issuer_prefix) - 1)) {
-        issuer = slist->data + sizeof(issuer_prefix) - 1;
+      if(!strncmp(slist->data, issuer_prefix, CURL_CSTRLEN(issuer_prefix))) {
+        issuer = slist->data + CURL_CSTRLEN(issuer_prefix);
       }
-      if(!strncmp(slist->data, subject_prefix, sizeof(subject_prefix) - 1)) {
-        subject = slist->data + sizeof(subject_prefix) - 1;
+      if(!strncmp(slist->data, subject_prefix, CURL_CSTRLEN(subject_prefix))) {
+        subject = slist->data + CURL_CSTRLEN(subject_prefix);
       }
     }
 
diff --git a/tests/libtest/lib505.c b/tests/libtest/lib505.c
index 7abaacd14e..bf1310fcd2 100644
--- a/tests/libtest/lib505.c
+++ b/tests/libtest/lib505.c
@@ -41,8 +41,8 @@ static CURLcode test_lib505(const char *URL)
   struct curl_slist *headerlist;
   struct curl_slist *temp;
 
-  static const char *buf_1 = "RNFR 505";
-  static const char *buf_2 = "RNTO 505-forreal";
+  static const char buf_1[] = "RNFR 505";
+  static const char buf_2[] = "RNTO 505-forreal";
 
   if(!libtest_arg2) {
     curl_mfprintf(stderr, "Usage: <url> <file-to-upload>\n");
diff --git a/tests/libtest/lib508.c b/tests/libtest/lib508.c
index 7ecf2665c4..20aa1ff865 100644
--- a/tests/libtest/lib508.c
+++ b/tests/libtest/lib508.c
@@ -56,7 +56,7 @@ static CURLcode test_lib508(const char *URL)
   struct t508_WriteThis pooh;
 
   pooh.readptr = testdata;
-  pooh.sizeleft = sizeof(testdata) - 1;
+  pooh.sizeleft = CURL_CSTRLEN(testdata);
 
   if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
     curl_mfprintf(stderr, "curl_global_init() failed\n");
diff --git a/tests/libtest/lib536.c b/tests/libtest/lib536.c
index e25922062a..d6347545f5 100644
--- a/tests/libtest/lib536.c
+++ b/tests/libtest/lib536.c
@@ -37,7 +37,7 @@ static CURLcode test_lib536(const char *URL)
   CURL *curl;
   struct curl_slist *host = NULL;
 
-  static const char *url_with_proxy = "http://usingproxy.test/";
+  static const char url_with_proxy[] = "http://usingproxy.test/";
   const char *url_without_proxy = libtest_arg2;
 
   if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
diff --git a/tests/libtest/lib544.c b/tests/libtest/lib544.c
index 02dc11f39b..013c2ab32b 100644
--- a/tests/libtest/lib544.c
+++ b/tests/libtest/lib544.c
@@ -63,7 +63,7 @@ static CURLcode test_lib544(const char *URL)
   easy_setopt(curl, CURLOPT_HEADER, 1L); /* include header */
 
   /* Update the original data to detect non-copy. */
-  curlx_strcopy(teststring, sizeof(teststring), "FAIL", strlen("FAIL"));
+  curlx_strcopy(teststring, sizeof(teststring), "FAIL", CURL_CSTRLEN("FAIL"));
 
   {
     CURL *curl2;
diff --git a/tests/libtest/lib547.c b/tests/libtest/lib547.c
index e44c16b55b..66ad32afbb 100644
--- a/tests/libtest/lib547.c
+++ b/tests/libtest/lib547.c
@@ -29,7 +29,7 @@
 #include "first.h"
 
 static const char t547_uploadthis[] = "this is the blurb we want to upload\n";
-static size_t const t547_datalen = sizeof(t547_uploadthis) - 1;
+static const size_t t547_datalen = CURL_CSTRLEN(t547_uploadthis);
 
 static size_t t547_read_cb(char *ptr, size_t size, size_t nmemb, void *clientp)
 {
diff --git a/tests/libtest/lib554.c b/tests/libtest/lib554.c
index 98a7ba7fdc..ce4348a8d7 100644
--- a/tests/libtest/lib554.c
+++ b/tests/libtest/lib554.c
@@ -69,7 +69,7 @@ static CURLcode t554_test_once(const char *URL, bool oldstyle)
   struct t554_WriteThis pooh2;
 
   pooh.readptr = testdata;
-  pooh.sizeleft = sizeof(testdata) - 1;
+  pooh.sizeleft = CURL_CSTRLEN(testdata);
 
   /* Fill in the file upload field */
   if(oldstyle) {
@@ -99,7 +99,7 @@ static CURLcode t554_test_once(const char *URL, bool oldstyle)
      a file upload but still using the callback */
 
   pooh2.readptr = testdata;
-  pooh2.sizeleft = sizeof(testdata) - 1;
+  pooh2.sizeleft = CURL_CSTRLEN(testdata);
 
   /* Fill in the file upload field */
   formrc = curl_formadd(&formpost,
diff --git a/tests/libtest/lib555.c b/tests/libtest/lib555.c
index 9e11aae7d7..e2cdfbc971 100644
--- a/tests/libtest/lib555.c
+++ b/tests/libtest/lib555.c
@@ -33,7 +33,7 @@
 #include "first.h"
 
 static const char t555_uploadthis[] = "this is the blurb we want to upload\n";
-static size_t const t555_datalen = sizeof(t555_uploadthis) - 1;
+static const size_t t555_datalen = CURL_CSTRLEN(t555_uploadthis);
 
 static size_t t555_read_cb(char *ptr, size_t size, size_t nmemb, void *clientp)
 {
diff --git a/tests/libtest/lib571.c b/tests/libtest/lib571.c
index 37b93e5390..4f506bc3b9 100644
--- a/tests/libtest/lib571.c
+++ b/tests/libtest/lib571.c
@@ -44,7 +44,7 @@ static int rtp_packet_count = 0;
 
 static size_t rtp_write(char *data, size_t size, size_t nmemb, void *stream)
 {
-  static const char *RTP_DATA = "$_1234\n\0Rsdf";
+  static const char RTP_DATA[] = "$_1234\n\0Rsdf";
 
   int channel = RTP_PKT_CHANNEL(data);
   int message_size;
diff --git a/tests/libtest/lib643.c b/tests/libtest/lib643.c
index eaf75e8fe1..c2aed4f0d2 100644
--- a/tests/libtest/lib643.c
+++ b/tests/libtest/lib643.c
@@ -69,7 +69,7 @@ static CURLcode t643_test_once(const char *URL, bool oldstyle)
 
   pooh.readptr = testdata;
   if(testnum == 643)
-    datasize = (curl_off_t)(sizeof(testdata) - 1);
+    datasize = (curl_off_t)CURL_CSTRLEN(testdata);
   pooh.sizeleft = datasize;
 
   curl = curl_easy_init();
@@ -123,7 +123,7 @@ static CURLcode t643_test_once(const char *URL, bool oldstyle)
 
   pooh2.readptr = testdata;
   if(testnum == 643)
-    datasize = (curl_off_t)(sizeof(testdata) - 1);
+    datasize = (curl_off_t)CURL_CSTRLEN(testdata);
   pooh2.sizeleft = datasize;
 
   part = curl_mime_addpart(mime);
diff --git a/tests/libtest/lib654.c b/tests/libtest/lib654.c
index 0494d580ab..a10dc94478 100644
--- a/tests/libtest/lib654.c
+++ b/tests/libtest/lib654.c
@@ -92,7 +92,7 @@ static CURLcode test_lib654(const char *URL)
 
   /* Prepare the callback structure. */
   pooh.readptr = testdata;
-  pooh.sizeleft = (curl_off_t)(sizeof(testdata) - 1);
+  pooh.sizeleft = (curl_off_t)CURL_CSTRLEN(testdata);
   pooh.freecount = 0;
 
   /* Build the mime tree. */
diff --git a/tests/libtest/lib655.c b/tests/libtest/lib655.c
index 3dd70dfa73..5e1f0990e2 100644
--- a/tests/libtest/lib655.c
+++ b/tests/libtest/lib655.c
@@ -25,7 +25,7 @@
 
 #include "testtrace.h"
 
-static const char *TEST_DATA_STRING = "Test data";
+static const char TEST_DATA_STRING[] = "Test data";
 static int cb_count = 0;
 
 static int resolver_alloc_cb_fail(void *resolver_state, void *reserved,
diff --git a/tests/libtest/lib667.c b/tests/libtest/lib667.c
index 28a9cde6d2..38158dc2b4 100644
--- a/tests/libtest/lib667.c
+++ b/tests/libtest/lib667.c
@@ -82,7 +82,7 @@ static CURLcode test_lib667(const char *URL)
 
   /* Prepare the callback structure. */
   pooh.readptr = testdata;
-  pooh.sizeleft = (curl_off_t)(sizeof(testdata) - 1);
+  pooh.sizeleft = (curl_off_t)CURL_CSTRLEN(testdata);
 
   /* Build the mime tree. */
   mime = curl_mime_init(curl);
diff --git a/tests/libtest/lib668.c b/tests/libtest/lib668.c
index cd9897f7e9..fd59a0c3f9 100644
--- a/tests/libtest/lib668.c
+++ b/tests/libtest/lib668.c
@@ -77,7 +77,7 @@ static CURLcode test_lib668(const char *URL)
 
   /* Prepare the callback structures. */
   pooh1.readptr = testdata;
-  pooh1.sizeleft = sizeof(testdata) - 1;
+  pooh1.sizeleft = CURL_CSTRLEN(testdata);
   pooh2 = pooh1;
 
   /* Build the mime tree. */
diff --git a/tests/libtest/lib677.c b/tests/libtest/lib677.c
index 106fbb2603..6a6c5ef5a9 100644
--- a/tests/libtest/lib677.c
+++ b/tests/libtest/lib677.c
@@ -77,8 +77,8 @@ static CURLcode test_lib677(const char *URL)
 
       if(!state) {
         CURLcode ec;
-        ec = curl_easy_send(curl, testcmd + pos,
-                            sizeof(testcmd) - 1 - pos, &len);
+        ec = curl_easy_send(curl, testcmd + pos, CURL_CSTRLEN(testcmd) - pos,
+                            &len);
         if(ec == CURLE_AGAIN) {
           continue;
         }
@@ -92,7 +92,7 @@ static CURLcode test_lib677(const char *URL)
           pos += len;
         else
           pos = 0;
-        if(pos == sizeof(testcmd) - 1) {
+        if(pos == CURL_CSTRLEN(testcmd)) {
           state++;
           pos = 0;
         }
diff --git a/tests/libtest/lib757.c b/tests/libtest/lib757.c
index 325f3b7b6b..378c78cf81 100644
--- a/tests/libtest/lib757.c
+++ b/tests/libtest/lib757.c
@@ -24,7 +24,7 @@
 #include "first.h"
 
 static const char t757_data[] = "<title>fun-times</title>";
-static size_t const t757_datalen = sizeof(t757_data) - 1;
+static const size_t t757_datalen = CURL_CSTRLEN(t757_data);
 
 static size_t read_757(char *buffer, size_t size, size_t nitems, void *arg)
 {
diff --git a/tests/server/mqttd.c b/tests/server/mqttd.c
index 189ac41bec..732bcd2efb 100644
--- a/tests/server/mqttd.c
+++ b/tests/server/mqttd.c
@@ -178,8 +178,8 @@ static int connack(FILE *dump, curl_socket_t fd)
     MQTT_MSG_CONNACK, 0x02,
     0x00, 0x00
   };
-  ssize_t rc;
   const char *label = "CONNACK";
+  ssize_t rc;
 
   if(m_config.pingresp_as_connack) {
     /* Send a PINGRESP (0xD0) with remaining_length=2 and payload
@@ -260,8 +260,8 @@ static int disconnect(FILE *dump, curl_socket_t fd)
     MQTT_MSG_DISCONNECT, 0x00,
     0x00, 0x00 /* extra bytes for malformed variant */
   };
-  size_t pktlen = 2;
   const char *label = "DISCONNECT";
+  size_t pktlen = 2;
   ssize_t rc;
 
   if(m_config.disconnect_malformed) {
@@ -638,8 +638,8 @@ static curl_socket_t mqttit(curl_socket_t fd)
         }
       }
       else {
-        const char *def = "this is random payload yes yes it is";
-        publish(dump, fd, packet_id, topic, def, strlen(def));
+        static const char def[] = "this is random payload yes yes it is";
+        publish(dump, fd, packet_id, topic, def, CURL_CSTRLEN(def));
       }
       disconnect(dump, fd);
     }
diff --git a/tests/server/rtspd.c b/tests/server/rtspd.c
index fe2dded9fa..7e6c8ef43b 100644
--- a/tests/server/rtspd.c
+++ b/tests/server/rtspd.c
@@ -106,18 +106,18 @@ struct rtspd_httprequest {
 #define END_OF_HEADERS "\r\n\r\n"
 
 /* sent as reply to a QUIT */
-static const char *docquit_rtsp = "HTTP/1.1 200 Goodbye" END_OF_HEADERS;
+static const char docquit_rtsp[] = "HTTP/1.1 200 Goodbye" END_OF_HEADERS;
 
 /* sent as reply to a CONNECT */
-static const char *docconnect =
+static const char docconnect[] =
   "HTTP/1.1 200 Mighty fine indeed" END_OF_HEADERS;
 
 /* sent as reply to a "bad" CONNECT */
-static const char *docbadconnect =
+static const char docbadconnect[] =
   "HTTP/1.1 501 Forbidden you fool" END_OF_HEADERS;
 
 /* send back this on HTTP 404 file not found */
-static const char *doc404_HTTP =
+static const char doc404_HTTP[] =
   "HTTP/1.1 404 Not Found\r\n"
   "Server: " RTSPDVERSION "\r\n"
   "Connection: close\r\n"
@@ -133,13 +133,13 @@ static const char *doc404_HTTP =
   "</BODY></HTML>\n";
 
 /* send back this on RTSP 404 file not found */
-static const char *doc404_RTSP = "RTSP/1.0 404 Not Found\r\n"
+static const char doc404_RTSP[] = "RTSP/1.0 404 Not Found\r\n"
   "Server: " RTSPDVERSION
   END_OF_HEADERS;
 
 /* Default size to send away fake RTP data */
 #define RTP_DATA_SIZE 12
-static const char *RTP_DATA = "$_1234\n\0Rsdf";
+static const char RTP_DATA[] = "$_1234\n\0Rsdf";
 
 static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
 {
@@ -267,16 +267,17 @@ static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
           logmsg("Found a reply-servercmd section!");
           do {
             rtp_size_err = 0;
-            if(!strncmp(CMD_AUTH_REQUIRED, ptr, strlen(CMD_AUTH_REQUIRED))) {
+            if(!strncmp(CMD_AUTH_REQUIRED, ptr,
+                        CURL_CSTRLEN(CMD_AUTH_REQUIRED))) {
               logmsg("instructed to require authorization header");
               req->auth_req = TRUE;
             }
-            else if(!strncmp(CMD_IDLE, ptr, strlen(CMD_IDLE))) {
+            else if(!strncmp(CMD_IDLE, ptr, CURL_CSTRLEN(CMD_IDLE))) {
               logmsg("instructed to idle");
               req->rcmd = RCMD_IDLE;
               req->open = TRUE;
             }
-            else if(!strncmp(CMD_STREAM, ptr, strlen(CMD_STREAM))) {
+            else if(!strncmp(CMD_STREAM, ptr, CURL_CSTRLEN(CMD_STREAM))) {
               logmsg("instructed to stream");
               req->rcmd = RCMD_STREAM;
             }
@@ -404,7 +405,7 @@ static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
   if(req->pipe)
     /* we do have a full set, advance the checkindex to after the end of the
        headers, for the pipelining case mostly */
-    req->checkindex += (end - line) + strlen(END_OF_HEADERS);
+    req->checkindex += (end - line) + CURL_CSTRLEN(END_OF_HEADERS);
 
   /* **** Persistence ****
    *
@@ -427,7 +428,7 @@ static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
          ignore the content-length, we return as soon as all headers
          have been received */
       curl_off_t clen;
-      const char *p = line + strlen("Content-Length:");
+      const char *p = line + CURL_CSTRLEN("Content-Length:");
       if(curlx_str_numblanks(&p, &clen)) {
         /* this assumes that a zero Content-Length is valid */
         logmsg("Found invalid '%s' in the request", line);
@@ -442,7 +443,7 @@ static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
       break;
     }
     else if(!CURL_STRNICMP("Transfer-Encoding: chunked", line,
-                           strlen("Transfer-Encoding: chunked"))) {
+                           CURL_CSTRLEN("Transfer-Encoding: chunked"))) {
       /* chunked data coming in */
       chunked = TRUE;
     }
@@ -506,12 +507,12 @@ static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
   if(!req->pipe &&
      req->open &&
      req->prot_version >= 11 &&
-     req->reqbuf + req->offset > end + strlen(END_OF_HEADERS) &&
-     (!strncmp(req->reqbuf, "GET", strlen("GET")) ||
-      !strncmp(req->reqbuf, "HEAD", strlen("HEAD")))) {
+     req->reqbuf + req->offset > end + CURL_CSTRLEN(END_OF_HEADERS) &&
+     (!strncmp(req->reqbuf, "GET", CURL_CSTRLEN("GET")) ||
+      !strncmp(req->reqbuf, "HEAD", CURL_CSTRLEN("HEAD")))) {
     /* If we have a persistent connection, HTTP version >= 1.1
        and GET/HEAD request, enable pipelining. */
-    req->checkindex = (end - req->reqbuf) + strlen(END_OF_HEADERS);
+    req->checkindex = (end - req->reqbuf) + CURL_CSTRLEN(END_OF_HEADERS);
     req->pipelining = TRUE;
   }
 
@@ -523,7 +524,7 @@ static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
     end = strstr(line, END_OF_HEADERS);
     if(!end)
       break;
-    req->checkindex += (end - line) + strlen(END_OF_HEADERS);
+    req->checkindex += (end - line) + CURL_CSTRLEN(END_OF_HEADERS);
     req->pipe--;
   }
 
@@ -535,7 +536,8 @@ static int rtspd_ProcessRequest(struct rtspd_httprequest *req)
     return 1; /* done */
 
   if(req->cl > 0) {
-    if(req->cl <= req->offset - (end - req->reqbuf) - strlen(END_OF_HEADERS))
+    if(req->cl <= req->offset - (end - req->reqbuf) -
+                  CURL_CSTRLEN(END_OF_HEADERS))
       return 1; /* done */
     else
       return 0; /* not complete yet */
diff --git a/tests/server/socksd.c b/tests/server/socksd.c
index b0b5b6771c..4de563b06c 100644
--- a/tests/server/socksd.c
+++ b/tests/server/socksd.c
@@ -102,9 +102,9 @@ static void socksd_resetdefaults(void)
   curlx_strcopy(s_config.addr, sizeof(s_config.addr),
                 CONFIG_ADDR, strlen(CONFIG_ADDR));
   curlx_strcopy(s_config.user, sizeof(s_config.user),
-                "user", strlen("user"));
+                "user", CURL_CSTRLEN("user"));
   curlx_strcopy(s_config.password, sizeof(s_config.password),
-                "password", strlen("password"));
+                "password", CURL_CSTRLEN("password"));
 }
 
 static void socksd_getconfig(void)
diff --git a/tests/server/sws.c b/tests/server/sws.c
index 8190002af2..e47ba7fc3d 100644
--- a/tests/server/sws.c
+++ b/tests/server/sws.c
@@ -141,10 +141,10 @@ static const char *cmdfile = "log/server.cmd";
 static const char *end_of_headers = END_OF_HEADERS;
 
 /* sent as reply to a QUIT */
-static const char *docquit_sws = "HTTP/1.1 200 Goodbye" END_OF_HEADERS;
+static const char docquit_sws[] = "HTTP/1.1 200 Goodbye" END_OF_HEADERS;
 
 /* send back this on 404 file not found */
-static const char *doc404 =
+static const char doc404[] =
   "HTTP/1.1 404 Not Found\r\n"
   "Server: " SWSVERSION "\r\n"
   "Connection: close\r\n"
@@ -262,29 +262,29 @@ static int sws_parse_servercmd(struct sws_httprequest *req)
     while(cmd && cmdsize) {
       const char *check;
 
-      if(!strncmp(CMD_AUTH_REQUIRED, cmd, strlen(CMD_AUTH_REQUIRED))) {
+      if(!strncmp(CMD_AUTH_REQUIRED, cmd, CURL_CSTRLEN(CMD_AUTH_REQUIRED))) {
         logmsg("instructed to require authorization header");
         req->auth_req = TRUE;
       }
-      else if(!strncmp(CMD_IDLE, cmd, strlen(CMD_IDLE))) {
+      else if(!strncmp(CMD_IDLE, cmd, CURL_CSTRLEN(CMD_IDLE))) {
         logmsg("instructed to idle");
         req->rcmd = RCMD_IDLE;
         req->open = TRUE;
       }
-      else if(!strncmp(CMD_STREAM, cmd, strlen(CMD_STREAM))) {
+      else if(!strncmp(CMD_STREAM, cmd, CURL_CSTRLEN(CMD_STREAM))) {
         logmsg("instructed to stream");
         req->rcmd = RCMD_STREAM;
       }
       else if(!strncmp(CMD_CONNECTIONMONITOR, cmd,
-                       strlen(CMD_CONNECTIONMONITOR))) {
+                       CURL_CSTRLEN(CMD_CONNECTIONMONITOR))) {
         logmsg("enabled connection monitoring");
         req->connmon = TRUE;
       }
-      else if(!strncmp(CMD_UPGRADE, cmd, strlen(CMD_UPGRADE))) {
+      else if(!strncmp(CMD_UPGRADE, cmd, CURL_CSTRLEN(CMD_UPGRADE))) {
         logmsg("enabled upgrade");
         req->upgrade = TRUE;
       }
-      else if(!strncmp(CMD_SWSCLOSE, cmd, strlen(CMD_SWSCLOSE))) {
+      else if(!strncmp(CMD_SWSCLOSE, cmd, CURL_CSTRLEN(CMD_SWSCLOSE))) {
         logmsg("swsclose: close this connection after response");
         req->close = TRUE;
       }
@@ -292,7 +292,7 @@ static int sws_parse_servercmd(struct sws_httprequest *req)
         logmsg("instructed to skip this number of bytes %d", num);
         req->skip = num;
       }
-      else if(!strncmp(CMD_NOEXPECT, cmd, strlen(CMD_NOEXPECT))) {
+      else if(!strncmp(CMD_NOEXPECT, cmd, CURL_CSTRLEN(CMD_NOEXPECT))) {
         logmsg("instructed to reject Expect: 100-continue");
         req->noexpect = TRUE;
       }
@@ -591,7 +591,7 @@ static int sws_ProcessRequest(struct sws_httprequest *req)
          ignore the content-length, we return as soon as all headers
          have been received */
       curl_off_t clen;
-      const char *p = line + strlen("Content-Length:");
+      const char *p = line + CURL_CSTRLEN("Content-Length:");
       if(curlx_str_numblanks(&p, &clen)) {
         /* this assumes that a zero Content-Length is valid */
         logmsg("Found invalid '%s' in the request", line);
@@ -608,12 +608,13 @@ static int sws_ProcessRequest(struct sws_httprequest *req)
         logmsg("... but going to abort after %zu bytes", req->cl);
     }
     else if(!CURL_STRNICMP("Transfer-Encoding: chunked", line,
-                           strlen("Transfer-Encoding: chunked"))) {
+                           CURL_CSTRLEN("Transfer-Encoding: chunked"))) {
       /* chunked data coming in */
       chunked = TRUE;
     }
-    else if(req->noexpect && !CURL_STRNICMP("Expect: 100-continue", line,
-                                            strlen("Expect: 100-continue"))) {
+    else if(req->noexpect &&
+            !CURL_STRNICMP("Expect: 100-continue", line,
+                           CURL_CSTRLEN("Expect: 100-continue"))) {
       if(req->cl)
         req->cl = 0;
       req->skipall = TRUE;
@@ -709,8 +710,8 @@ static int sws_ProcessRequest(struct sws_httprequest *req)
      req->prot_version >= 11 &&
      req->reqbuf + req->offset > end + strlen(end_of_headers) &&
      !req->cl &&
-     (!strncmp(req->reqbuf, "GET", strlen("GET")) ||
-      !strncmp(req->reqbuf, "HEAD", strlen("HEAD")))) {
+     (!strncmp(req->reqbuf, "GET", CURL_CSTRLEN("GET")) ||
+      !strncmp(req->reqbuf, "HEAD", CURL_CSTRLEN("HEAD")))) {
     /* If we have a persistent connection, HTTP version >= 1.1
        and GET/HEAD request, enable pipelining. */
     req->checkindex = (end - req->reqbuf) + strlen(end_of_headers);
@@ -771,10 +772,10 @@ static int sws_send_doc(curl_socket_t sock, struct sws_httprequest *req)
   case RCMD_STREAM: {
     static const char streamthis[] = "a string to stream 01234567890\n";
     for(;;) {
-      written = swrite(sock, streamthis, sizeof(streamthis) - 1);
+      written = swrite(sock, streamthis, CURL_CSTRLEN(streamthis));
       if(got_exit_signal)
         return -1;
-      if(written != (ssize_t)(sizeof(streamthis) - 1)) {
+      if(written != (ssize_t)CURL_CSTRLEN(streamthis)) {
         logmsg("Stopped streaming");
         break;
       }
@@ -2325,8 +2326,9 @@ static int test_sws(int argc, const char *argv[])
             logmsg("====> Client disconnect %d", req->connmon);
 
             if(req->connmon) {
-              const char *keepopen = "[DISCONNECT]\n";
-              storerequest(keepopen, strlen(keepopen), REQUEST_DUMP_FILENAME);
+              static const char keepopen[] = "[DISCONNECT]\n";
+              storerequest(keepopen, CURL_CSTRLEN(keepopen),
+                           REQUEST_DUMP_FILENAME);
             }
 
             if(!req->open)
diff --git a/tests/tunit/tool1720.c b/tests/tunit/tool1720.c
index 80e3c157ba..486d57e630 100644
--- a/tests/tunit/tool1720.c
+++ b/tests/tunit/tool1720.c
@@ -28,7 +28,7 @@ static CURLcode test_tool1720(const char *arg)
 {
   UNITTEST_BEGIN_SIMPLE
 
-  static const char *check[] = {
+  static const char * const check[] = {
     "",
     "(null)",
     "filename",
diff --git a/tests/unit/unit1303.c b/tests/unit/unit1303.c
index 50cdaa12f1..52a7ea9c43 100644
--- a/tests/unit/unit1303.c
+++ b/tests/unit/unit1303.c
@@ -85,7 +85,7 @@ static CURLcode test_unit1303(const char *arg)
     const char *comment;
   };
 
-  const struct timetest run[] = {
+  static const struct timetest run[] = {
     /* both timeouts set, not connecting */
     {BASE + 4, 0,      10000, 8000, FALSE, 6000, "6 seconds should be left"},
     {BASE + 4, 990000, 10000, 8000, FALSE, 5010, "5010 ms should be left"},
diff --git a/tests/unit/unit1395.c b/tests/unit/unit1395.c
index d25d0e3005..a286303977 100644
--- a/tests/unit/unit1395.c
+++ b/tests/unit/unit1395.c
@@ -35,7 +35,7 @@ static CURLcode test_unit1395(const char *arg)
     const char *output;
   };
 
-  const struct dotdot pairs[] = {
+  static const struct dotdot pairs[] = {
     { "/%2f%2e%2e%2f/../a", "/a" },
     { "/%2f%2e%2e%2f/../", "/" },
     { "/%2f%2e%2e%2f/.", "/%2f%2e%2e%2f/" },
diff --git a/tests/unit/unit1396.c b/tests/unit/unit1396.c
index 5b03e092bb..1dd3c17112 100644
--- a/tests/unit/unit1396.c
+++ b/tests/unit/unit1396.c
@@ -51,7 +51,7 @@ static CURLcode test_unit1396(const char *arg)
   };
 
   /* unescape, this => that */
-  const struct test list1[] = {
+  static const struct test list1[] = {
     { "%61", 3, "a", 1 },
     { "%61a", 4, "aa", 2 },
     { "%61b", 4, "ab", 2 },
@@ -67,7 +67,7 @@ static CURLcode test_unit1396(const char *arg)
     { NULL, 0, NULL, 0 } /* end of list marker */
   };
   /* escape, this => that */
-  const struct test list2[] = {
+  static const struct test list2[] = {
     { "a", 1, "a", 1 },
     { "/", 1, "%2F", 3 },
     { "a=b", 3, "a%3Db", 5 },
diff --git a/tests/unit/unit1398.c b/tests/unit/unit1398.c
index 7f2267e438..2147a4a283 100644
--- a/tests/unit/unit1398.c
+++ b/tests/unit/unit1398.c
@@ -34,7 +34,7 @@ static CURLcode test_unit1398(const char *arg)
 
   int rc;
   char buf[3] = { 'b', 'u', 'g' };
-  static const char *str = "bug";
+  static const char str[] = "bug";
   int width = 3;
   char output[130];
 
diff --git a/tests/unit/unit1625.c b/tests/unit/unit1625.c
index 9ca59b9402..21e37370c1 100644
--- a/tests/unit/unit1625.c
+++ b/tests/unit/unit1625.c
@@ -41,8 +41,8 @@ static CURLcode test_unit1625(const char *arg)
   char *large;
   size_t i;
   const size_t large_value_len = MAX_HTTP_RESP_HEADER_SIZE;
-  const size_t large_prefix_len = strlen("Encoding: ");
-  const size_t large_suffix_len = strlen(", chunked");
+  const size_t large_prefix_len = CURL_CSTRLEN("Encoding: ");
+  const size_t large_suffix_len = CURL_CSTRLEN(", chunked");
   static const struct check1625 list[] = {
     /* basic case */
     { "Encoding: gzip, chunked", "Encoding:", "chunked", TRUE },
diff --git a/tests/unit/unit1627.c b/tests/unit/unit1627.c
index 1d1f598358..06bd30cff5 100644
--- a/tests/unit/unit1627.c
+++ b/tests/unit/unit1627.c
@@ -32,7 +32,7 @@ static CURLcode test_unit1627(const char *arg)
 
   size_t i, j;
   /* existing schemes in different cases */
-  static const char *okay[] = {
+  static const char * const okay[] = {
     /* all upper */
     "DICT", "FILE", "FTP", "FTPS", "GOPHER", "GOPHERS", "HTTP", "HTTPS",
     "IMAP", "IMAPS", "LDAP", "LDAPS", "MQTT", "MQTTS", "POP3", "POP3S",
@@ -50,7 +50,7 @@ static CURLcode test_unit1627(const char *arg)
     "TELNEt", "tFTP", "Ws", "wSS",
   };
   /* non-existing schemes */
-  static const char *notokay[] = {
+  static const char * const notokay[] = {
     "a", "A", "htt", "ttp", "httt", "http+", "HTTPP", "HTTPPS", "HTTSP",
     "GROPHER", "D1CT", "AbG", "zLQp", "mNrtW", "PkY", "bVcxZq", "LmO",
     "iUhyT", "rEwQA", "xSdfG", "nBvC", "pOiuY", "tRewQ", "aSdfG", "hJkl",
diff --git a/tests/unit/unit1650.c b/tests/unit/unit1650.c
index 4e307474fd..299a19bfd4 100644
--- a/tests/unit/unit1650.c
+++ b/tests/unit/unit1650.c
@@ -54,8 +54,10 @@ static CURLcode test_unit1650(const char *arg)
   };
 
   static const struct dohrequest req[] = {
-    {"test.host.name", CURL_DNS_TYPE_A, DNS_Q1, sizeof(DNS_Q1)-1, DOH_OK },
-    {"test.host.name", CURL_DNS_TYPE_AAAA, DNS_Q2, sizeof(DNS_Q2)-1, DOH_OK },
+    {"test.host.name",
+     CURL_DNS_TYPE_A, DNS_Q1, CURL_CSTRLEN(DNS_Q1), DOH_OK },
+    {"test.host.name",
+     CURL_DNS_TYPE_AAAA, DNS_Q2, CURL_CSTRLEN(DNS_Q2), DOH_OK },
     {"zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
      ".host.name",
      CURL_DNS_TYPE_AAAA, NULL, 0, DOH_DNS_BAD_LABEL }
@@ -235,7 +237,7 @@ static CURLcode test_unit1650(const char *arg)
   }
 
   /* pass all sizes into the decoder until full */
-  for(i = 0; i < sizeof(full49) - 1; i++) {
+  for(i = 0; i < CURL_CSTRLEN(full49); i++) {
     struct dohentry d;
     DOHcode rc;
     memset(&d, 0, sizeof(d));
@@ -267,8 +269,8 @@ static CURLcode test_unit1650(const char *arg)
     struct dohentry d;
     struct dohaddr *a;
     memset(&d, 0, sizeof(d));
-    rc = doh_resp_decode((const unsigned char *)full49,
-                         sizeof(full49) - 1, CURL_DNS_TYPE_A, &d);
+    rc = doh_resp_decode((const unsigned char *)full49, CURL_CSTRLEN(full49),
+                         CURL_DNS_TYPE_A, &d);
     fail_if(d.numaddr != 1, "missing address");
     a = &d.addr[0];
     p = &a->ip.v4[0];
diff --git a/tests/unit/unit1655.c b/tests/unit/unit1655.c
index ff3dc53481..55e9020989 100644
--- a/tests/unit/unit1655.c
+++ b/tests/unit/unit1655.c
@@ -132,9 +132,9 @@ static CURLcode test_unit1655(const char *arg)
     const size_t buflen = sizeof(buffer);
     const size_t magic1 = 9765;
     size_t olen1 = magic1;
-    static const char *sunshine1 = "a.com";
-    static const char *dotshine1 = "a.com.";
-    static const char *sunshine2 = "aa.com";
+    static const char sunshine1[] = "a.com";
+    static const char dotshine1[] = "a.com.";
+    static const char sunshine2[] = "aa.com";
     size_t olen2;
     DOHcode ret2;
     size_t olen;
diff --git a/tests/unit/unit1664.c b/tests/unit/unit1664.c
index 17a04a37f2..f4574d485c 100644
--- a/tests/unit/unit1664.c
+++ b/tests/unit/unit1664.c
@@ -41,7 +41,7 @@ static CURLcode test_unit1664(const char *arg)
 {
   UNITTEST_BEGIN(t1664_setup())
 
-  static const char *wordparse[] = {
+  static const char * const wordparse[] = {
     "word",
     "word ",
     " word ",
@@ -78,7 +78,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *qwords[] = {
+    static const char * const qwords[] = {
       "\"word\"",
       "\"word",
       "word\"",
@@ -112,7 +112,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *single[] = {
+    static const char * const single[] = {
       "a",
       "aa",
       "A",
@@ -133,7 +133,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *single[] = {
+    static const char * const single[] = {
       "a",
       "aa",
       "A",
@@ -156,7 +156,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *single[] = {
+    static const char * const single[] = {
       "a",
       "aa",
       "A",
@@ -177,7 +177,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *nums[] = {
+    static const char * const nums[] = {
       "1",
       "10000",
       "1234",
@@ -313,7 +313,7 @@ static CURLcode test_unit1664(const char *arg)
 
   {
     /* CURL_OFF_T is typically 9223372036854775807 */
-    static const char *nums[] = {
+    static const char * const nums[] = {
       "9223372036854775807", /* 2^63 -1 */
       "9223372036854775808", /* 2^63 */
       "18446744073709551615", /* 2^64 - 1 */
@@ -347,7 +347,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *newl[] = {
+    static const char * const newl[] = {
       "a",
       "aa",
       "A",
@@ -372,7 +372,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *nums[] = {
+    static const char * const nums[] = {
       "1",
       "1000",
       "1234",
@@ -399,7 +399,7 @@ static CURLcode test_unit1664(const char *arg)
   }
 
   {
-    static const char *nums[] = {
+    static const char * const nums[] = {
       "1",
       "1000",
       "1234",
@@ -427,7 +427,7 @@ static CURLcode test_unit1664(const char *arg)
 
   {
     /* CURL_OFF_T is typically 2^63-1 */
-    static const char *nums[] = {
+    static const char * const nums[] = {
       "777777777777777777777", /* 2^63 -1 */
       "1000000000000000000000", /* 2^63 */
       "111111111111111111111",
@@ -451,7 +451,7 @@ static CURLcode test_unit1664(const char *arg)
 
   {
     /* CURL_OFF_T is typically 2^63-1 */
-    static const char *nums[] = {
+    static const char * const nums[] = {
       "7FFFFFFFFFFFFFFF", /* 2^63 -1 */
       "8000000000000000", /* 2^63 */
       "1111111111111111",
diff --git a/tests/unit/unit1666.c b/tests/unit/unit1666.c
index c2f20c977a..cf272da42f 100644
--- a/tests/unit/unit1666.c
+++ b/tests/unit/unit1666.c
@@ -36,7 +36,7 @@ struct test_1666 {
 };
 
 /* the size of the object needs to deduct the null-terminator */
-#define OID(x) x, sizeof(x) - 1
+#define OID(x) STRCONST(x)
 
 static bool test1666(const struct test_1666 *spec, size_t i,
                      struct dynbuf *dbuf)
diff --git a/tests/unit/unit1675.c b/tests/unit/unit1675.c
index 7e869651d0..1d7c44d461 100644
--- a/tests/unit/unit1675.c
+++ b/tests/unit/unit1675.c
@@ -38,7 +38,7 @@ static CURLcode test_unit1675(const char *arg)
       const char *in;
       const char *out;
     };
-    const struct ipv4_test tests[] = {
+    static const struct ipv4_test tests[] = {
       { "0x.0x.0x.0x", NULL }, /* invalid hex */
       { "0x.0x.0x", NULL }, /* invalid hex */
       { "0x.0x", NULL }, /* invalid hex */
@@ -146,7 +146,7 @@ static CURLcode test_unit1675(const char *arg)
       unsigned int query;
       const char *out;
     };
-    const struct urlencode_test tests[] = {
+    static const struct urlencode_test tests[] = {
       { "http://leave\x01/hello\x01world", FALSE, QUERY_NO,
         "http://leave\x01/hello%01world" },
       { "http://leave/hello\x01world", FALSE, QUERY_NO,
@@ -204,7 +204,7 @@ static CURLcode test_unit1675(const char *arg)
       const char *out_host;
       const char *out_zone;
     };
-    const struct ipv6_test tests[] = {
+    static const struct ipv6_test tests[] = {
       { "[::1]", "[::1]", NULL },
       { "[fe80::1%eth0]", "[fe80::1]", "eth0" },
       { "[fe80::1%25eth0]", "[fe80::1]", "eth0" },
@@ -260,7 +260,7 @@ static CURLcode test_unit1675(const char *arg)
       const char *out_path;
       bool fine;
     };
-    const struct file_test tests[] = {
+    static const struct file_test tests[] = {
       { "file:///etc/hosts", "/etc/hosts", TRUE },
       { "file://localhost/etc/hosts", "/etc/hosts", TRUE },
       { "file://apple/etc/hosts", "/etc/hosts", FALSE },
@@ -317,7 +317,7 @@ static CURLcode test_unit1675(const char *arg)
       const char *path;
       bool expect_match;
     };
-    const struct origin_test tests[] = {
+    static const struct origin_test tests[] = {
       { "http://host:123/x", "http", "host", "123", "/y", TRUE },
       { "http://host:123/x", NULL, "host", "123", "/y", TRUE },
       { "http://host:123/x", NULL, NULL, NULL, "/y", TRUE },
@@ -395,7 +395,7 @@ loop_end:
       const char *options;
       size_t offset;
     };
-    const struct test tests[] = {
+    static const struct test tests[] = {
       { CURLUE_OK, "foo:bar@host", NULL, 0, "foo", "bar", "o", 8 },
       { CURLUE_OK, "foo:bar;abc@host", "imap", 0, "foo", "bar", "abc", 12 },
       { CURLUE_OK, "foo:bar;abc@host", NULL, 0, "foo", "bar;abc", "o", 12 },
diff --git a/tests/unit/unit2603.c b/tests/unit/unit2603.c
index 0198ccf7f4..f2ec4f6b90 100644
--- a/tests/unit/unit2603.c
+++ b/tests/unit/unit2603.c
@@ -48,7 +48,7 @@ static void check_eq(const char *s, const char *exp_s, const char *name)
 }
 
 struct tcase {
-  const char **input;
+  const char * const *input;
   const char *default_scheme;
   const char *custom_method;
   const char *method;
@@ -117,7 +117,7 @@ static CURLcode test_unit2603(const char *arg)
   UNITTEST_BEGIN_SIMPLE
 
 #ifndef CURL_DISABLE_HTTP
-  static const char *T1_INPUT[] = {
+  static const char * const T1_INPUT[] = {
     "GET /path HTTP/1.1\r\nHost: test.curl.se\r\n\r\n",
     NULL,
   };
@@ -128,7 +128,7 @@ static CURLcode test_unit2603(const char *arg)
     T1_INPUT, "https", NULL, "GET", "https", NULL, "/path", 1, 0
   };
 
-  static const char *T2_INPUT[] = {
+  static const char * const T2_INPUT[] = {
     "GET /path HTT",
     "P/1.1\r\nHost: te",
     "st.curl.se\r\n\r",
@@ -139,7 +139,7 @@ static CURLcode test_unit2603(const char *arg)
     T2_INPUT, NULL, NULL, "GET", NULL, NULL, "/path", 1, 8
   };
 
-  static const char *T3_INPUT[] = {
+  static const char * const T3_INPUT[] = {
     "GET ftp://ftp.curl.se/xxx?a=2 HTTP/1.1\r\nContent-Length: 0\r",
     "\nUser-Agent: xxx\r\n\r\n",
     NULL,
@@ -148,7 +148,7 @@ static CURLcode test_unit2603(const char *arg)
     T3_INPUT, NULL, NULL, "GET", "ftp", "ftp.curl.se", "/xxx?a=2", 2, 0
   };
 
-  static const char *T4_INPUT[] = {
+  static const char * const T4_INPUT[] = {
     "CONNECT ftp.curl.se:123 HTTP/1.1\r\nContent-Length: 0\r\n",
     "User-Agent: xxx\r\n",
     "nothing:  \r\n\r\n\n\n",
@@ -158,7 +158,7 @@ static CURLcode test_unit2603(const char *arg)
     T4_INPUT, NULL, NULL, "CONNECT", NULL, "ftp.curl.se:123", NULL, 3, 2
   };
 
-  static const char *T6_INPUT[] = {
+  static const char * const T6_INPUT[] = {
     "PUT /path HTTP/1.1\nHost: test.curl.se\n\n123",
     NULL,
   };
@@ -167,7 +167,7 @@ static CURLcode test_unit2603(const char *arg)
   };
 
   /* test a custom method with space, #19543 */
-  static const char *T7_INPUT[] = {
+  static const char * const T7_INPUT[] = {
     "IN SANE /path HTTP/1.1\r\nContent-Length: 0\r\n\r\n",
     NULL,
   };
diff --git a/tests/unit/unit3200.c b/tests/unit/unit3200.c
index 3a7a37597c..23e5d56713 100644
--- a/tests/unit/unit3200.c
+++ b/tests/unit/unit3200.c
@@ -45,7 +45,7 @@ static CURLcode test_unit3200(const char *arg)
 #define C1024 C256 C256 C256 C256
 #define C4096 C1024 C1024 C1024 C1024
 
-  static const char *filecontents[] = {
+  static const char * const filecontents[] = {
     /* Both should be read */
     "LINE1\n"
     "LINE2 NEWLINE\n",
diff --git a/tests/unit/unit3205.c b/tests/unit/unit3205.c
index 039b679d0a..234d8ae933 100644
--- a/tests/unit/unit3205.c
+++ b/tests/unit/unit3205.c
@@ -420,7 +420,7 @@ static CURLcode test_unit3205(const char *arg)
 #endif
   };
 
-  static const char *cs_test_string =
+  static const char cs_test_string[] =
     "TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:"
     "TLS_CHACHA20_POLY1305_SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:"
     "ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:"
@@ -561,11 +561,12 @@ static CURLcode test_unit3205(const char *arg)
     if(test->id >= 0x0011 && test->id < 0x0017) {
       if(expect && !memcmp(expect, "EDH-", 4)) {
         curlx_strcopy(alt, sizeof(alt), expect, strlen(expect));
-        expect = (const char *)memcpy(alt, "DHE-", sizeof("DHE-") - 1);
+        expect = memcpy(alt, "DHE-", CURL_CSTRLEN("DHE-"));
       }
       if(expect && !memcmp(expect + 4, "EDH-", 4)) {
         curlx_strcopy(alt, sizeof(alt), expect, strlen(expect));
-        expect = (const char *)memcpy(alt + 4, "DHE-", sizeof("DHE-") - 1) - 4;
+        expect = memcpy(alt + 4, "DHE-", CURL_CSTRLEN("DHE-"));
+        expect -= 4;
       }
     }
 
diff --git a/tests/unit/unit3400.c b/tests/unit/unit3400.c
index 060cc61799..364a2b540f 100644
--- a/tests/unit/unit3400.c
+++ b/tests/unit/unit3400.c
@@ -56,13 +56,13 @@ static void check_capsule_hdr(size_t payload_len,
 
 static void test_capsule_encap_udp_hdr_boundaries(void)
 {
-  const unsigned char p0[] = { 0x00, 0x01, 0x00 };
-  const unsigned char p62[] = { 0x00, 0x3F, 0x00 };
-  const unsigned char p63[] = { 0x00, 0x40, 0x40, 0x00 };
-  const unsigned char p64[] = { 0x00, 0x40, 0x41, 0x00 };
-  const unsigned char p16382[] = { 0x00, 0x7F, 0xFF, 0x00 };
-  const unsigned char p16383[] = { 0x00, 0x80, 0x00, 0x40, 0x00, 0x00 };
-  const unsigned char p16384[] = { 0x00, 0x80, 0x00, 0x40, 0x01, 0x00 };
+  static const unsigned char p0[] = { 0x00, 0x01, 0x00 };
+  static const unsigned char p62[] = { 0x00, 0x3F, 0x00 };
+  static const unsigned char p63[] = { 0x00, 0x40, 0x40, 0x00 };
+  static const unsigned char p64[] = { 0x00, 0x40, 0x41, 0x00 };
+  static const unsigned char p16382[] = { 0x00, 0x7F, 0xFF, 0x00 };
+  static const unsigned char p16383[] = { 0x00, 0x80, 0x00, 0x40, 0x00, 0x00 };
+  static const unsigned char p16384[] = { 0x00, 0x80, 0x00, 0x40, 0x01, 0x00 };
 
   check_capsule_hdr(0, p0, sizeof(p0));
   check_capsule_hdr(62, p62, sizeof(p62));
@@ -139,7 +139,7 @@ static void test_capsule_sequential_decode(void)
   CURLcode err;
   size_t nread;
   /* Two back-to-back 3-byte UDP capsules */
-  const unsigned char two_caps[] = {
+  static const unsigned char two_caps[] = {
     0x00, 0x04, 0x00, 0x11, 0x22, 0x33,   /* capsule 1: [0x11,0x22,0x33] */
     0x00, 0x04, 0x00, 0xAA, 0xBB, 0xCC    /* capsule 2: [0xAA,0xBB,0xCC] */
   };
@@ -186,13 +186,15 @@ static void test_capsule_decode_paths(void)
   unsigned char out[8];
   CURLcode err = CURLE_OK;
   size_t nread;
-  const unsigned char invalid_type[] = { 0x01 };
-  const unsigned char partial_len[] = { 0x00, 0x40 };
-  const unsigned char invalid_context[] = { 0x00, 0x01, 0x01 };
-  const unsigned char invalid_caps_len[] = { 0x00, 0x00, 0x00 };
-  const unsigned char partial_payload[] = { 0x00, 0x04, 0x00, 0x11, 0x22 };
-  const unsigned char payload_3b[] = { 0x00, 0x04, 0x00, 0x11, 0x22, 0x33 };
-  const unsigned char payload_empty[] = { 0x00, 0x01, 0x00 };
+  static const unsigned char invalid_type[] = { 0x01 };
+  static const unsigned char partial_len[] = { 0x00, 0x40 };
+  static const unsigned char invalid_context[] = { 0x00, 0x01, 0x01 };
+  static const unsigned char invalid_caps_len[] = { 0x00, 0x00, 0x00 };
+  static const unsigned char partial_payload[] = { 0x00, 0x04, 0x00, 0x11,
+                                                   0x22 };
+  static const unsigned char payload_3b[] = { 0x00, 0x04, 0x00,
+                                              0x11, 0x22, 0x33 };
+  static const unsigned char payload_empty[] = { 0x00, 0x01, 0x00 };
 
   Curl_bufq_init2(&q, 32, 4, BUFQ_OPT_NONE);