diff --git a/lib/dpif-netlink-rtnl.c b/lib/dpif-netlink-rtnl.c
index 4829b5fbf19..c3c31ebd3c7 100644
--- a/lib/dpif-netlink-rtnl.c
+++ b/lib/dpif-netlink-rtnl.c
@@ -255,7 +255,7 @@ dpif_netlink_rtnl_verify(const struct netdev_tunnel_config *tnl_cfg,
     case OVS_VPORT_TYPE_UNSPEC:
     case __OVS_VPORT_TYPE_MAX:
     default:
-        err = EOPNOTSUPP;
+        OVS_NOT_REACHED();
     }
 
     ofpbuf_delete(reply);