diff -r 2577fdc3a458 -r 29c413a7dfb5 hgext3rd/topic/__init__.py
--- a/hgext3rd/topic/__init__.py	Thu Apr 19 16:25:17 2018 +0200
+++ b/hgext3rd/topic/__init__.py	Thu Apr 19 16:27:13 2018 +0200
@@ -600,7 +600,7 @@
                         " '_' and '.' characters")
             raise error.Abort(_("invalid topic name: '%s'") % topic, hint=helptxt)
 
-    compat.startpager(ui, 'topics')
+    ui.pager('topics')
 
     if list:
         if clear or rev:
@@ -681,7 +681,7 @@
         topic = repo.currenttopic
     if topic is None:
         branch = repo[None].branch()
-    compat.startpager(ui, 'stack')
+    ui.pager('stack')
     return stack.showstack(ui, repo, branch=branch, topic=topic, opts=opts)
 
 @command('debugcb|debugconvertbookmark', [