diff --git a/lib/zebra.h b/lib/zebra.h
index 30377fd..ed3024d 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -215,6 +215,10 @@
 
 #endif /* BSDI_NRL */
 
+#if !defined(__GNUC__) || __GNUC__ < 2 || __GNUC_MINOR__ < 5
+#define __attribute__(x)
+#endif  /* !__GNUC__ */
+
 /*  The definition of struct in_pktinfo is missing in old version of
     GLIBC 2.1 (Redhat 6.1).  */
 #if defined (GNU_LINUX) && ! defined (HAVE_INPKTINFO)