diff --git a/src/gmp/gmp-h.in b/src/gmp/gmp-h.in
index b5581d848..8a70b1e25 100644
--- a/src/gmp/gmp-h.in
+++ b/src/gmp/gmp-h.in
@@ -419,11 +419,28 @@ typedef __mpq_struct *mpq_ptr;
 /* gcc has __inline__ in all modes, including strict ansi.  Give a prototype
    for an inline too, so as to correctly specify "dllimport" on windows, in
    case the function is called rather than inlined.  */
+
 #ifdef __GNUC__
-#define __GMP_EXTERN_INLINE      extern __inline__
+#if defined(__APPLE_CC__) && (__APPLE_CC__ != 1) /* FSF GCC sets this flag to 1\
+ on Apple machines */
+
+#if ! (__APPLE_CC__ >= 5465 && __STDC_VERSION__ >= 199901L)
+#define __GMP_EXTERN_INLINE extern __inline__
 #define __GMP_INLINE_PROTOTYPES  1
 #endif
 
+#else /*GNU CC*/
+
+#if defined(__GNUC_STDC_INLINE__) || defined (__GNUC_GNU_INLINE__)
+#define __GMP_EXTERN_INLINE extern __inline__ __attribute__((__gnu_inline__))
+#else
+#define __GMP_EXTERN_INLINE extern __inline__
+#endif
+#define __GMP_INLINE_PROTOTYPES  1
+
+#endif
+#endif
+
 /* DEC C (eg. version 5.9) supports "static __inline foo()", even in -std1
    strict ANSI mode.  Inlining is done even when not optimizing (ie. -O0
    mode, which is the default), but an unnecessary local copy of foo is