diff --git a/src/network/wait-online/link.c b/src/network/wait-online/link.c
index d0f3347617..e820a7a20f 100644
--- a/src/network/wait-online/link.c
+++ b/src/network/wait-online/link.c
@@ -15,6 +15,7 @@ int link_new(Manager *m, Link **ret, int ifindex, const char *ifname) {
 
         assert(m);
         assert(ifindex > 0);
+        assert(ifname);
 
         n = strdup(ifname);
         if (!n)