diff --git a/manila_tempest_tests/tests/api/test_share_network_subnets.py b/manila_tempest_tests/tests/api/test_share_network_subnets.py
index a16dd3c9..1ae5351a 100644
--- a/manila_tempest_tests/tests/api/test_share_network_subnets.py
+++ b/manila_tempest_tests/tests/api/test_share_network_subnets.py
@@ -76,7 +76,7 @@ class ShareNetworkSubnetsTest(base.BaseSharesMixedTest):
             "share_network_id", "mtu"
         ]
         if utils.is_microversion_ge(CONF.share.max_api_microversion, '2.78'):
-            keys.extend('metadata')
+            keys.extend(['metadata'])
 
         # Default subnet was created during share network creation
         self.assertIsNone(default_subnet['availability_zone'])