goto out;
 
 found:
-       req.mgmt_class         = ureq.mgmt_class;
-       req.mgmt_class_version = ureq.mgmt_class_version;
-       memcpy(req.method_mask, ureq.method_mask, sizeof req.method_mask);
-       memcpy(req.oui,         ureq.oui,         sizeof req.oui);
+       if (ureq.mgmt_class) {
+               req.mgmt_class         = ureq.mgmt_class;
+               req.mgmt_class_version = ureq.mgmt_class_version;
+               memcpy(req.method_mask, ureq.method_mask, sizeof req.method_mask);
+               memcpy(req.oui,         ureq.oui,         sizeof req.oui);
+       }
 
        agent = ib_register_mad_agent(file->port->ib_dev, file->port->port_num,
                                      ureq.qpn ? IB_QPT_GSI : IB_QPT_SMI,
-                                     &req, 0, send_handler, recv_handler,
-                                     file);
+                                     ureq.mgmt_class ? &req : NULL,
+                                     0, send_handler, recv_handler, file);
        if (IS_ERR(agent)) {
                ret = PTR_ERR(agent);
                goto out;