diff --git a/webpack_loader/loaders.py b/webpack_loader/loaders.py
index 9e6c52aa..487eb444 100644
--- a/webpack_loader/loaders.py
+++ b/webpack_loader/loaders.py
@@ -171,3 +171,6 @@ def get_bundle(self, _bundle_name):
                 "url": "http://localhost/static/webpack_bundles/test.bundle.js",
             }
         ]
+
+    def get_asset_by_source_filename(self, name):
+        return None