extern int c_toupper (int c) _GL_ATTRIBUTE_CONST;
-#if defined __GNUC__ && defined __OPTIMIZE__ && !defined __OPTIMIZE_SIZE__ && !defined NO_C_CTYPE_MACROS
+#if (defined __GNUC__ && !defined __STRICT_ANSI__ && defined __OPTIMIZE__ \
+ && !defined __OPTIMIZE_SIZE__ && !defined NO_C_CTYPE_MACROS)
/* ASCII optimizations. */