diff --git a/src/libsystemd/sd-netlink/netlink-util.c b/src/libsystemd/sd-netlink/netlink-util.c
index 0650f0b475..4012725f4c 100644
--- a/src/libsystemd/sd-netlink/netlink-util.c
+++ b/src/libsystemd/sd-netlink/netlink-util.c
@@ -274,6 +274,9 @@ int rtnl_resolve_link_alternative_name(sd_netlink **rtnl, const char *name) {
 
         assert(name);
 
+        if (!ifname_valid_full(name, IFNAME_VALID_ALTERNATIVE))
+                return -EINVAL;
+
         if (!rtnl)
                 rtnl = &our_rtnl;
         if (!*rtnl) {