diff --git a/tempest/api/volume/test_volume_absolute_limits.py b/tempest/api/volume/test_volume_absolute_limits.py
index 836e489..870b9f0 100644
--- a/tempest/api/volume/test_volume_absolute_limits.py
+++ b/tempest/api/volume/test_volume_absolute_limits.py
@@ -21,7 +21,10 @@
 CONF = config.CONF
 
 
-class AbsoluteLimitsTests(base.BaseVolumeTest):
+# NOTE(zhufl): This inherits from BaseVolumeAdminTest because
+# it requires force_tenant_isolation=True, which need admin
+# credentials to create non-admin users for the tests.
+class AbsoluteLimitsTests(base.BaseVolumeAdminTest):
 
     # avoid existing volumes of pre-defined tenant
     force_tenant_isolation = True