diff --git a/src/repdav/textgrid_dav_provider.py b/src/repdav/textgrid_dav_provider.py
index 8b5d9692e7c297b8a7f5f6822fdd21dc1b303d1a..1838f17459a153b1594ba1268f644e7d5d5801c8 100644
--- a/src/repdav/textgrid_dav_provider.py
+++ b/src/repdav/textgrid_dav_provider.py
@@ -101,7 +101,7 @@ class TextgridProject(DAVCollection):
         # return names
         #
         # path resolution has to be rewritten before we can work with resource titles
-        response = self._tgsearch.list_project_root(self.project_id, self._sid)
+        response = self._tgsearch.list_project_root(self._project_id, self._sid)
         names = []
         for result in response.result:
             names.append(result.object_value.generic.generated.textgrid_uri.value)