diff --git a/tempest/common/isolated_creds.py b/tempest/common/isolated_creds.py
index 99b04ce..1ce1e39 100644
--- a/tempest/common/isolated_creds.py
+++ b/tempest/common/isolated_creds.py
@@ -316,12 +316,9 @@
         net_client = self.network_admin_client
         for cred in self.isolated_net_resources:
             network, subnet, router = self.isolated_net_resources.get(cred)
-            credentials = self.isolated_creds.get(cred)
             LOG.debug("Clearing network: %(network)s, "
-                      "subnet: %(subnet)s, router: %(router)s for credentials "
-                      "%(credentials)",
-                      {'network': network, 'subnet': subnet,
-                       'router': router, 'credentials': credentials})
+                      "subnet: %(subnet)s, router: %(router)s",
+                      {'network': network, 'subnet': subnet, 'router': router})
             if (not self.network_resources or
                 self.network_resources.get('router')):
                 try: