diff -r df8d535216af -r 5dfe4e5cf9e4 hgext3rd/topic/flow.py
--- a/hgext3rd/topic/flow.py	Thu Nov 30 21:31:14 2017 -0800
+++ b/hgext3rd/topic/flow.py	Tue Dec 05 13:21:57 2017 +0100
@@ -48,7 +48,7 @@
 
 def wrapphasediscovery(orig, pushop):
     orig(pushop)
-    if pushop.publish:
+    if getattr(pushop, 'publish', False):
         if not util.safehasattr(pushop, 'remotephases'):
             msg = _('--publish flag only supported from Mercurial 4.4 and higher')
             raise error.Abort(msg)