diff --git a/tempest/scenario/test_large_ops.py b/tempest/scenario/test_large_ops.py
index 91b95a8..83b5aff 100644
--- a/tempest/scenario/test_large_ops.py
+++ b/tempest/scenario/test_large_ops.py
@@ -60,7 +60,7 @@
             self.image,
             flavor_id,
             min_count=CONF.scenario.large_ops_number,
-            security_groups=[secgroup])
+            security_groups=[{'name': secgroup['name']}])
         # needed because of bug 1199788
         params = {'name': name}
         _, server_list = self.servers_client.list_servers(params)