diff --git a/src/core/netif.c b/src/core/netif.c
index e95cb672..595fc58c 100644
--- a/src/core/netif.c
+++ b/src/core/netif.c
@@ -1714,6 +1714,10 @@ netif_find(const char *name)
   }
 
   num = (u8_t)atoi(&name[2]);
+  if (!num && (name[2] != 0)) {
+    /* this means atoi has failed */
+    return NULL;
+  }
 
   NETIF_FOREACH(netif) {
     if (num == netif->num &&