diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 4ca09580bc..6d9973eb04 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -19,7 +19,7 @@
 /* control stack frame */
 
 #undef INLINE
-#ifdef __OPTIMIZE__
+#if defined __GNUC__ && !defined __clang__
 #define INLINE inline
 #else
 #define INLINE static inline