diff --git a/zebra/interface.h b/zebra/interface.h
index 9a69dfa..0a6b036 100644
--- a/zebra/interface.h
+++ b/zebra/interface.h
@@ -221,7 +221,7 @@
 extern int if_subnet_delete (struct interface *, struct connected *);
 
 #ifdef HAVE_PROC_NET_DEV
-extern int ifstat_update_proc (void);
+extern void ifstat_update_proc (void);
 #endif /* HAVE_PROC_NET_DEV */
 #ifdef HAVE_NET_RT_IFLIST
 extern void ifstat_update_sysctl (void);