diff --git a/lib/curlx/base64.c b/lib/curlx/base64.c
index 7f51576f50..519b045cfe 100644
--- a/lib/curlx/base64.c
+++ b/lib/curlx/base64.c
@@ -149,7 +149,7 @@ CURLcode curlx_base64_decode(const char *src,
     pos += 3 - padding;
   }
 
-  /* Null-terminate */
+  /* null-terminate */
   *pos = '\0';
 
   /* Return the decoded data */
@@ -213,7 +213,7 @@ static CURLcode base64_encode(const char *table64,
     }
   }
 
-  /* Null-terminate */
+  /* null-terminate */
   *output = '\0';
 
   /* Return the pointer to the new data (allocated memory) */
diff --git a/lib/escape.c b/lib/escape.c
index 4aff583de1..a1a714f8f5 100644
--- a/lib/escape.c
+++ b/lib/escape.c
@@ -196,7 +196,7 @@ void curl_free(void *p)
  * Curl_hexencode()
  *
  * Converts binary input to lowercase hex-encoded ASCII output.
- * Null-terminated.
+ * null-terminated.
  */
 void Curl_hexencode(const unsigned char *src, size_t len, /* input length */
                     unsigned char *out, size_t olen) /* output buffer size */
diff --git a/lib/vauth/ntlm.c b/lib/vauth/ntlm.c
index 0be26b3cac..1efdb242db 100644
--- a/lib/vauth/ntlm.c
+++ b/lib/vauth/ntlm.c
@@ -341,7 +341,7 @@ CURLcode Curl_auth_decode_ntlm_type2_message(struct Curl_easy *data,
   /* NTLM type-2 message structure:
 
           Index  Description            Content
-            0    NTLMSSP Signature      Null-terminated ASCII "NTLMSSP"
+            0    NTLMSSP Signature      null-terminated ASCII "NTLMSSP"
                                         (0x4e544c4d53535000)
             8    NTLM Message Type      long (0x02000000)
            12    Target Name            security buffer
@@ -430,7 +430,7 @@ CURLcode Curl_auth_create_ntlm_type1_message(struct Curl_easy *data,
   /* NTLM type-1 message structure:
 
        Index  Description            Content
-         0    NTLMSSP Signature      Null-terminated ASCII "NTLMSSP"
+         0    NTLMSSP Signature      null-terminated ASCII "NTLMSSP"
                                      (0x4e544c4d53535000)
          8    NTLM Message Type      long (0x01000000)
         12    Flags                  long
@@ -549,13 +549,13 @@ CURLcode Curl_auth_create_ntlm_type3_message(struct Curl_easy *data,
   /* NTLM type-3 message structure:
 
           Index  Description            Content
-            0    NTLMSSP Signature      Null-terminated ASCII "NTLMSSP"
+            0    NTLMSSP Signature      null-terminated ASCII "NTLMSSP"
                                         (0x4e544c4d53535000)
             8    NTLM Message Type      long (0x03000000)
            12    LM/LMv2 Response       security buffer
            20    NTLM/NTLMv2 Response   security buffer
            28    Target Name            security buffer
-           36    username              security buffer
+           36    username               security buffer
            44    Workstation Name       security buffer
           (52)   Session Key            security buffer (*)
           (60)   Flags                  long (*)
diff --git a/projects/vms/curl_crtl_init.c b/projects/vms/curl_crtl_init.c
index 9c8e46761e..09c46dd03c 100644
--- a/projects/vms/curl_crtl_init.c
+++ b/projects/vms/curl_crtl_init.c
@@ -126,7 +126,7 @@ static int sys_trnlnm(const char *logname, char *value, int value_len)
 
   if($VMS_STATUS_SUCCESS(status)) {
 
-    /* Null-terminate and return the string */
+    /* null-terminate and return the string */
     /*--------------------------------------*/
     value[result] = '\0';
   }