diff --git a/health_check/contrib/db_heartbeat/backends.py b/health_check/contrib/db_heartbeat/backends.py
index e7fde43e..10976cc4 100644
--- a/health_check/contrib/db_heartbeat/backends.py
+++ b/health_check/contrib/db_heartbeat/backends.py
@@ -4,7 +4,7 @@
 
 
 class DatabaseHeartBeatCheck(BaseHealthCheckBackend):
-    """ Health check that runs a simple SELECT 1; query to test if the database connection is alive. """
+    """Health check that runs a simple SELECT 1; query to test if the database connection is alive."""
 
     def check_status(self):
         try: