diff --git a/scenario/scenario_base.py b/scenario/scenario_base.py
index 84e14a9..14b8cec 100644
--- a/scenario/scenario_base.py
+++ b/scenario/scenario_base.py
@@ -14,7 +14,7 @@
 
 
 class ScenarioTestsBase(test.HeatIntegrationTest):
-    "This class define common parameters for scenario tests"
+    """This class defines common parameters for scenario tests."""
 
     def setUp(self):
         super(ScenarioTestsBase, self).setUp()