diff --git a/swh/lister/gitlab/lister.py b/swh/lister/gitlab/lister.py
--- a/swh/lister/gitlab/lister.py
+++ b/swh/lister/gitlab/lister.py
@@ -16,6 +16,14 @@
     API_URL_INDEX_RE = re.compile(r'^.*/projects.*\&page=(\d+).*')
     MODEL = GitLabModel
 
+    @property
+    def CONFIG_BASE_FILENAME(self):
+        """One gitlab lister for all instances.  We discriminate between the
+        origin on a per instance basis in the table.
+
+        """
+        return 'lister-gitlab'
+
     @property
     def ADDITIONAL_CONFIG(self):
         """Override additional config as the 'credentials' structure change