--- a/hgext3rd/topic/stack.py
+++ b/hgext3rd/topic/stack.py
@@ -19,6 +19,9 @@
 if not util.safehasattr(context.basectx, 'orphan'):
     context.basectx.orphan = context.basectx.unstable
 
+if not util.safehasattr(context.basectx, 'isunstable'):
+    context.basectx.isunstable = context.basectx.troubled
+
 def getstack(repo, branch=None, topic=None):
     # XXX need sorting
     if topic is not None and branch is not None:
@@ -178,7 +181,7 @@
     data = {}
     revs = getstack(repo, branch, topic)[1:]
     data['changesetcount'] = len(revs)
-    data['troubledcount'] = len([r for r in revs if repo[r].troubled()])
+    data['troubledcount'] = len([r for r in revs if repo[r].isunstable()])
     deps, rdeps = builddependencies(repo, revs)
     data['headcount'] = len([r for r in revs if not rdeps[r]])
     data['behindcount'] = 0