--- a/hgext3rd/topic/__init__.py	Wed May 10 13:08:45 2017 +0200
+++ b/hgext3rd/topic/__init__.py	Wed May 10 13:03:05 2017 +0200
@@ -157,6 +157,10 @@
     if not isinstance(repo, localrepo.localrepository):
         return # this can be a peer in the ssh case (puzzling)
 
+    if repo.ui.config('experimental', 'thg.displaynames', None) is None:
+        repo.ui.setconfig('experimental', 'thg.displaynames', 'topics',
+                          source='topic-extension')
+
     class topicrepo(repo.__class__):
 
         def _restrictcapabilities(self, caps):