diff --git a/lib/curl_gssapi.c b/lib/curl_gssapi.c
index 650d1908d0..6220bac078 100644
--- a/lib/curl_gssapi.c
+++ b/lib/curl_gssapi.c
@@ -257,7 +257,7 @@ static OM_uint32 stub_gss_init_sec_context(
     }
 
     /* Token format: creds:target:type:padding */
-    used = curl_msnprintf(token, length, "%s:%.*s:%d:", creds,
+    used = curl_msnprintf(token, length, "%s:%.*s:%u:", creds,
                           (int)target_desc.length,
                           (const char *)target_desc.value,
                           ctx->sent);
diff --git a/lib/http_chunks.c b/lib/http_chunks.c
index aa45c79e38..6f9cc446f0 100644
--- a/lib/http_chunks.c
+++ b/lib/http_chunks.c
@@ -153,7 +153,8 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
         if(ch->hexindex == 0) {
           /* This is illegal data, we received junk where we expected
              a hexadecimal digit. */
-          failf(data, "chunk hex-length char not a hex digit: 0x%x", *buf);
+          failf(data, "chunk hex-length char not a hex digit: 0x%x",
+                (unsigned int)*buf);
           ch->state = CHUNK_FAILED;
           ch->last_code = CHUNKE_ILLEGAL_HEX;
           return CURLE_RECV_ERROR;
diff --git a/lib/mqtt.c b/lib/mqtt.c
index 8a1f5b1e96..eaf59e97c1 100644
--- a/lib/mqtt.c
+++ b/lib/mqtt.c
@@ -427,7 +427,7 @@ static CURLcode mqtt_verify_connack(struct Curl_easy *data)
 
   if(ptr[0] != 0x00 || ptr[1] != 0x00) {
     failf(data, "Expected %02x%02x but got %02x%02x",
-          0x00U, 0x00U, ptr[0], ptr[1]);
+          0x00U, 0x00U, (unsigned char)ptr[0], (unsigned char)ptr[1]);
     curlx_dyn_reset(&mq->recvbuf);
     return CURLE_WEIRD_SERVER_REPLY;
   }
diff --git a/lib/vquic/curl_ngtcp2.c b/lib/vquic/curl_ngtcp2.c
index d626610b3a..51b60432b0 100644
--- a/lib/vquic/curl_ngtcp2.c
+++ b/lib/vquic/curl_ngtcp2.c
@@ -2412,7 +2412,7 @@ static int quic_gtls_handshake_cb(gnutls_session_t session, unsigned int htype,
     DEBUGASSERT(data);
     if(!data)
       return 0;
-    CURL_TRC_CF(data, cf, "SSL message: %s %s [%d]",
+    CURL_TRC_CF(data, cf, "SSL message: %s %s [%u]",
                 incoming ? "<-" : "->", gtls_hs_msg_name(htype), htype);
     switch(htype) {
     case GNUTLS_HANDSHAKE_NEW_SESSION_TICKET: {
diff --git a/lib/vquic/curl_quiche.c b/lib/vquic/curl_quiche.c
index 8a24e1f6a5..0510515c28 100644
--- a/lib/vquic/curl_quiche.c
+++ b/lib/vquic/curl_quiche.c
@@ -563,7 +563,7 @@ static void cf_quiche_process_ev(struct Curl_cfilter *cf,
 
   default:
     CURL_TRC_CF(data, cf, "[%" PRIu64 "] recv, unhandled event %d",
-                stream->id, quiche_h3_event_type(ev));
+                stream->id, (int)quiche_h3_event_type(ev));
     break;
   }
 }
@@ -1051,7 +1051,7 @@ static CURLcode h3_open_stream(struct Curl_cfilter *cf,
       goto out;
     }
     else {
-      CURL_TRC_CF(data, cf, "send_request(%s) -> %" PRIu64,
+      CURL_TRC_CF(data, cf, "send_request(%s) -> %" PRId64,
                   Curl_bufref_ptr(&data->state.url), rv);
     }
     result = CURLE_SEND_ERROR;
diff --git a/lib/vtls/gtls.c b/lib/vtls/gtls.c
index 1b581cda88..9b6a4fab2e 100644
--- a/lib/vtls/gtls.c
+++ b/lib/vtls/gtls.c
@@ -127,7 +127,7 @@ static ssize_t gtls_pull(void *s, void *buf, size_t blen)
   }
 
   result = Curl_conn_cf_recv(cf->next, data, buf, blen, &nread);
-  CURL_TRC_CF(data, cf, "glts_pull(len=%zu) -> %d, %zd", blen, result, nread);
+  CURL_TRC_CF(data, cf, "glts_pull(len=%zu) -> %d, %zu", blen, result, nread);
   backend->gtls.io_result = result;
   if(result) {
     /* !checksrc! disable ERRNOVAR 1 */
@@ -793,7 +793,7 @@ static int gtls_handshake_cb(gnutls_session_t session, unsigned int htype,
   if(when) { /* after message has been processed */
     struct Curl_easy *data = CF_DATA_CURRENT(cf);
     if(data) {
-      CURL_TRC_CF(data, cf, "handshake: %s message type %d",
+      CURL_TRC_CF(data, cf, "handshake: %s message type %u",
                   incoming ? "incoming" : "outgoing", htype);
       switch(htype) {
       case GNUTLS_HANDSHAKE_NEW_SESSION_TICKET: {
@@ -1619,7 +1619,7 @@ CURLcode Curl_gtls_verifyserver(struct Curl_cfilter *cf,
 
   if(data->set.ssl.certinfo && chain.certs) {
     if(chain.num_certs > MAX_ALLOWED_CERT_AMOUNT) {
-      failf(data, "%u certificates is more than allowed (%u)",
+      failf(data, "%u certificates is more than allowed (%d)",
             chain.num_certs, MAX_ALLOWED_CERT_AMOUNT);
       result = CURLE_SSL_CONNECT_ERROR;
       goto out;
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 6b75492e97..abb30a0ff7 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -279,7 +279,7 @@ static CURLcode get_pkey_rsa(struct Curl_easy *data,
 #else
   RSA_get0_key(rsa, &n, &e, NULL);
 #endif /* HAVE_EVP_PKEY_GET_PARAMS */
-  BIO_printf(mem, "%d", n ? BN_num_bits(n) : 0);
+  BIO_printf(mem, "%d", (int)(n ? BN_num_bits(n) : 0));
   result = push_certinfo(data, mem, "RSA Public Key", i);
   if(!result) {
     result = print_pubkey_BN(rsa, n, i);
diff --git a/tests/libtest/cli_hx_download.c b/tests/libtest/cli_hx_download.c
index 81ffc19f25..af6df1449a 100644
--- a/tests/libtest/cli_hx_download.c
+++ b/tests/libtest/cli_hx_download.c
@@ -199,7 +199,7 @@ static int my_progress_d_cb(void *userdata,
           (struct rustls_connection *)tls->internals);
         assert(v);
         curl_mfprintf(stderr, "[t-%zu] info rustls TLS version 0x%x\n",
-                      t->idx, v);
+                      t->idx, (unsigned int)v);
         break;
       }
 #endif