diff -r 54d6dff699f0 -r 5c40dd2cf131 hgext3rd/topic/stack.py
--- a/hgext3rd/topic/stack.py	Fri Aug 26 14:14:04 2016 +0200
+++ b/hgext3rd/topic/stack.py	Fri Aug 26 14:23:31 2016 +0200
@@ -25,8 +25,12 @@
     if topic == repo.currenttopic:
         label = 'topic.active'
 
+    data = stackdata(repo, topic)
     fm.plain(_('### topic: %s\n') % ui.label(topic, label),
              label='topic.stack.summary.topic')
+    fm.plain(_('### branch: %s\n')
+             % '+'.join(data['branches']), # XXX handle multi branches
+             label='topic.stack.summary.branches')
 
     for idx, r in enumerate(getstack(repo, topic), 1):
         ctx = repo[r]