diff -r ce86f7bb4b7b -r 302be26a3fd8 hgext3rd/topic/stack.py
--- a/hgext3rd/topic/stack.py	Fri Aug 26 14:55:58 2016 +0200
+++ b/hgext3rd/topic/stack.py	Fri Aug 26 21:57:48 2016 +0200
@@ -26,8 +26,15 @@
         label = 'topic.active'
 
     data = stackdata(repo, topic)
-    fm.plain(_('### topic: %s\n') % ui.label(topic, label),
+    fm.plain(_('### topic: %s') % ui.label(topic, label),
              label='topic.stack.summary.topic')
+
+    if 1 < data['headcount']:
+        fm.plain(' (')
+        fm.plain('%d heads' % data['headcount'],
+                 label='topic.stack.summary.headcount.multiple')
+        fm.plain(')')
+    fm.plain('\n')
     fm.plain(_('### branch: %s')
              % '+'.join(data['branches']), # XXX handle multi branches
              label='topic.stack.summary.branches')