diff --git a/core/src/zeit/connector/tests/test_contract.py b/core/src/zeit/connector/tests/test_contract.py
index 6a2be5659f..42f72490b3 100644
--- a/core/src/zeit/connector/tests/test_contract.py
+++ b/core/src/zeit/connector/tests/test_contract.py
@@ -117,7 +117,9 @@ def test_delitem_collection_raises_error_if_children_are_locked(self):
         self.assertEqual([], self.listCollection('http://xml.zeit.de/testing'))
         self.add_resource('one')
         self.add_resource('two')
-        self.add_resource('http://xml.zeit.de/testing/folder/file')
+        collection = Resource(None, None, 'image', BytesIO(b''), None, 'httpd/unix-directory')
+        self.connector['http://xml.zeit.de/testing/folder'] = collection
+        self.add_resource('folder/file')
         self.connector.lock(
             'http://xml.zeit.de/testing/one',
             'external',