diff --git a/lib/if.c b/lib/if.c
index 212b236..a32cee0 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -768,7 +768,8 @@
 {
   struct interface *ifp;
 
-  return ((ifp = if_lookup_by_name(name)) != NULL) ? ifp->ifindex : 0;
+  return ((ifp = if_lookup_by_name_len(name, strnlen(name, IFNAMSIZ))) != NULL)
+  	 ? ifp->ifindex : 0;
 }
 #endif