--- libmariadb/getopt.c
+++ libmariadb/getopt.c
@@ -38,7 +38,7 @@
 #include <config.h>
 #endif
 
-#if (!defined (__STDC__) || !__STDC__) && !defined(MSDOS) && !defined(OS2)
+#if (!defined (__STDC__) || !__STDC__) && !defined(MSDOS) && !defined(OS2) && !(defined _MSC_VER && defined __clang__)
 /* This is a separate conditional since some stdc systems
    reject `defined (const)'.  */
 #ifndef const