diff --git a/zebra/misc_null.c b/zebra/misc_null.c
index c8cc47d..0680726 100644
--- a/zebra/misc_null.c
+++ b/zebra/misc_null.c
@@ -7,9 +7,15 @@
 #include "zebra/zebra_fpm.h"
 
 void ifstat_update_proc (void) { return; }
+#ifdef HAVE_SYS_WEAK_ALIAS_PRAGMA
 #pragma weak rtadv_config_write = ifstat_update_proc
 #pragma weak irdp_config_write = ifstat_update_proc
 #pragma weak ifstat_update_sysctl = ifstat_update_proc
+#else
+void rtadv_config_write (struct vty *vty, struct interface *ifp) { return; }
+void irdp_config_write (struct vty *vty, struct interface *ifp) { return; }
+void ifstat_update_sysctl (void) { return; }
+#endif
 
 void
 zfpm_trigger_update (struct route_node *rn, const char *reason)