diff --git a/src/flask_session/base.py b/src/flask_session/base.py
index 2958a636..fa94c537 100644
--- a/src/flask_session/base.py
+++ b/src/flask_session/base.py
@@ -193,7 +193,7 @@ def __init__(
     # INTERNAL METHODS
 
     def _generate_sid(self, session_id_length: int) -> str:
-        """Generate a random session id."""
+        """Generate a random session id.  """
         new_sid = secrets.token_urlsafe(session_id_length)
         if self._retrieve_session_data(new_sid):
             raise RuntimeError("Session ID already exists in the database.")