diff --git a/lib_acl/include/stdlib/acl_define_unix.h b/lib_acl/include/stdlib/acl_define_unix.h
index b74c872..52cdef7 100644
--- a/lib_acl/include/stdlib/acl_define_unix.h
+++ b/lib_acl/include/stdlib/acl_define_unix.h
@@ -55,7 +55,11 @@
 #  define acl_assert assert
 # endif
 
+#if defined(__GNUC__)
+# define ACL_API __attribute__((visibility("default")))
+#else
 # define ACL_API
+#endif
 
 #if 1
 # define	ACL_ETIMEDOUT		ETIMEDOUT