diff --git a/tests/test_periodiccache.py b/tests/test_periodiccache.py
index f874f9041..b2bd8ba2b 100644
--- a/tests/test_periodiccache.py
+++ b/tests/test_periodiccache.py
@@ -26,7 +26,9 @@ def test_ttl_cache():
         assert 'a' in cache1h
 
         t.move_to("2021-09-01 05:59:59 +00:00")
+        assert 'a' not in cache
         assert 'a' in cache1h
 
         t.move_to("2021-09-01 06:00:00 +00:00")
+        assert 'a' not in cache
         assert 'a' not in cache1h