diff --git a/net/net.c b/net/net.c
index 16a87cc..77b35ea 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1134,6 +1134,11 @@
 
 void qmp_netdev_add(Netdev *netdev, Error **errp)
 {
+    if (!id_wellformed(netdev->id)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
+        return;
+    }
+
     net_client_init1(netdev, true, errp);
 }