diff --git a/test_runner/fixtures/neon_fixtures.py b/test_runner/fixtures/neon_fixtures.py
index d3aadbe612..a6fd4792dd 100644
--- a/test_runner/fixtures/neon_fixtures.py
+++ b/test_runner/fixtures/neon_fixtures.py
@@ -1393,7 +1393,7 @@ def neon_env_builder(
     top_output_dir: Path,
     pageserver_virtual_file_io_engine: str,
     pageserver_default_tenant_config_compaction_algorithm: Optional[Dict[str, Any]],
-    pageserver_aux_file_policy: Optional[AuxFileStore] = None,
+    pageserver_aux_file_policy: Optional[AuxFileStore],
 ) -> Iterator[NeonEnvBuilder]:
     """
     Fixture to create a Neon environment for test.