diff --git a/src/api/z3.h b/src/api/z3.h
index 47e3a1fe1..bb7611030 100644
--- a/src/api/z3.h
+++ b/src/api/z3.h
@@ -21,10 +21,6 @@ Notes:
 #ifndef _Z3__H_
 #define _Z3__H_
 
-#ifdef __GNUC__
-# define Z3_API __attribute__ ((visibility ("default")))
-#endif
-
 #include<stdio.h>
 #include"z3_macros.h"
 #include"z3_api.h"
diff --git a/src/api/z3_macros.h b/src/api/z3_macros.h
index a4a0cb4be..7a0b6857c 100644
--- a/src/api/z3_macros.h
+++ b/src/api/z3_macros.h
@@ -35,7 +35,11 @@
 #endif
 
 #ifndef Z3_API
-#define Z3_API
+# ifdef __GNUC__
+#  define Z3_API __attribute__ ((visibility ("default")))
+# else
+#  define Z3_API
+# endif
 #endif 
 
 #ifndef DEFINE_TYPE