diff --git a/lib/md5.c b/lib/md5.c
index d372c6da9fbb5f..b819d3924021d1 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -484,29 +484,35 @@ static void MD5_Final(unsigned char *result, MD5_CTX *ctx)
 
 #endif /* CRYPTO LIBS */
 
-/* Disable this picky gcc-8 compiler warning */
-#if defined(__GNUC__) && (__GNUC__ >= 8)
-#pragma GCC diagnostic ignored "-Wcast-function-type"
-#endif
-
 const HMAC_params Curl_HMAC_MD5[] = {
   {
-    (HMAC_hinit_func) MD5_Init,           /* Hash initialization function. */
-    (HMAC_hupdate_func) MD5_Update,       /* Hash update function. */
-    (HMAC_hfinal_func) MD5_Final,         /* Hash computation end function. */
-    sizeof(MD5_CTX),                      /* Size of hash context structure. */
-    64,                                   /* Maximum key length. */
-    16                                    /* Result size. */
+    /* Hash initialization function. */
+    CURLX_FUNCTION_CAST(HMAC_hinit_func, MD5_Init),
+    /* Hash update function. */
+    CURLX_FUNCTION_CAST(HMAC_hupdate_func, MD5_Update),
+    /* Hash computation end function. */
+    CURLX_FUNCTION_CAST(HMAC_hfinal_func, MD5_Final),
+    /* Size of hash context structure. */
+    sizeof(MD5_CTX),
+    /* Maximum key length. */
+    64,
+    /* Result size. */
+    16
   }
 };
 
 const MD5_params Curl_DIGEST_MD5[] = {
   {
-    (Curl_MD5_init_func) MD5_Init,      /* Digest initialization function */
-    (Curl_MD5_update_func) MD5_Update,  /* Digest update function */
-    (Curl_MD5_final_func) MD5_Final,    /* Digest computation end function */
-    sizeof(MD5_CTX),                    /* Size of digest context struct */
-    16                                  /* Result size */
+    /* Digest initialization function */
+    CURLX_FUNCTION_CAST(Curl_MD5_init_func, MD5_Init),
+    /* Digest update function */
+    CURLX_FUNCTION_CAST(Curl_MD5_update_func, MD5_Update),
+    /* Digest computation end function */
+    CURLX_FUNCTION_CAST(Curl_MD5_final_func, MD5_Final),
+    /* Size of digest context struct */
+    sizeof(MD5_CTX),
+    /* Result size */
+    16
   }
 };
 
diff --git a/src/tool_metalink.c b/src/tool_metalink.c
index f8effd3742fa89..4c4261472d5ffd 100644
--- a/src/tool_metalink.c
+++ b/src/tool_metalink.c
@@ -461,16 +461,11 @@ static void SHA256_Final(unsigned char digest[32], SHA256_CTX *ctx)
 
 #endif /* CRYPTO LIBS */
 
-/* Disable this picky gcc-8 compiler warning */
-#if defined(__GNUC__) && (__GNUC__ >= 8)
-#pragma GCC diagnostic ignored "-Wcast-function-type"
-#endif
-
 const digest_params MD5_DIGEST_PARAMS[] = {
   {
-    (Curl_digest_init_func) MD5_Init,
-    (Curl_digest_update_func) MD5_Update,
-    (Curl_digest_final_func) MD5_Final,
+    CURLX_FUNCTION_CAST(Curl_digest_init_func, MD5_Init),
+    CURLX_FUNCTION_CAST(Curl_digest_update_func, MD5_Update),
+    CURLX_FUNCTION_CAST(Curl_digest_final_func, MD5_Final),
     sizeof(MD5_CTX),
     16
   }
@@ -478,9 +473,9 @@ const digest_params MD5_DIGEST_PARAMS[] = {
 
 const digest_params SHA1_DIGEST_PARAMS[] = {
   {
-    (Curl_digest_init_func) SHA1_Init,
-    (Curl_digest_update_func) SHA1_Update,
-    (Curl_digest_final_func) SHA1_Final,
+    CURLX_FUNCTION_CAST(Curl_digest_init_func, SHA1_Init),
+    CURLX_FUNCTION_CAST(Curl_digest_update_func, SHA1_Update),
+    CURLX_FUNCTION_CAST(Curl_digest_final_func, SHA1_Final),
     sizeof(SHA_CTX),
     20
   }
@@ -488,9 +483,9 @@ const digest_params SHA1_DIGEST_PARAMS[] = {
 
 const digest_params SHA256_DIGEST_PARAMS[] = {
   {
-    (Curl_digest_init_func) SHA256_Init,
-    (Curl_digest_update_func) SHA256_Update,
-    (Curl_digest_final_func) SHA256_Final,
+    CURLX_FUNCTION_CAST(Curl_digest_init_func, SHA256_Init),
+    CURLX_FUNCTION_CAST(Curl_digest_update_func, SHA256_Update),
+    CURLX_FUNCTION_CAST(Curl_digest_final_func, SHA256_Final),
     sizeof(SHA256_CTX),
     32
   }