diff --git a/tests/abs_test.py b/tests/abs_test.py
index 534accde..19b3ffb7 100644
--- a/tests/abs_test.py
+++ b/tests/abs_test.py
@@ -1,6 +1,6 @@
-from abc import ABC
+from abc import ABC, abstractmethod
 from contextlib import contextmanager
-from datetime import timedelta, datetime, timezone
+from datetime import datetime, timezone
 
 import time
 from tests.utils import session_permanent, session_refresh_each_request
@@ -12,6 +12,7 @@ class ABSTestSession(ABC):
     def setup_filesystem(self):
         raise NotImplementedError
 
+    @abstractmethod
     def retrieve_stored_session(self, key, app):
         raise NotImplementedError
 
@@ -21,7 +22,6 @@ def test_default(self, app_utils,_session_permanent,
                                      _session_refresh_each_request):
         raise NotImplementedError
 
-
     def _default_test(self, app_utils, app):
         app_utils.test_session(app)
         app_utils.test_regenerate_session(app)
diff --git a/tests/test_dynamodb.py b/tests/test_dynamodb.py
index 0b38c25a..11d5440e 100644
--- a/tests/test_dynamodb.py
+++ b/tests/test_dynamodb.py
@@ -44,6 +44,9 @@ def setup_dynamodb(self):
                     }
                 )
 
+    def retrieve_stored_session(self, key, app):
+        return self.store.get_item(Key={"id": key}).get("Item")
+
     def test_dynamodb_default(self, app_utils):
         with self.setup_dynamodb():
             app = app_utils.create_app(