diff --git a/changelog.d/11359.misc b/changelog.d/11359.misc
new file mode 100644
index 0000000000..4720519cbc
--- /dev/null
+++ b/changelog.d/11359.misc
@@ -0,0 +1 @@
+Require all files in synapse/ and tests/ to pass mypy unless specifically excluded.
diff --git a/tests/storage/test_rollback_worker.py b/tests/storage/test_rollback_worker.py
index 0ce0892165..cfc8098af6 100644
--- a/tests/storage/test_rollback_worker.py
+++ b/tests/storage/test_rollback_worker.py
@@ -33,7 +33,7 @@ def fake_listdir(filepath: str) -> List[str]:
         A list of files and folders in the directory.
     """
     if filepath.endswith("full_schemas"):
-        return [SCHEMA_VERSION]
+        return [str(SCHEMA_VERSION)]
 
     return ["99_add_unicorn_to_database.sql"]