--- a/mercurial/obsolete.py	Thu Oct 19 12:33:53 2017 +0200
+++ b/mercurial/obsolete.py	Thu Oct 19 17:50:20 2017 +0200
@@ -1077,7 +1077,7 @@
 
     # Effect flag metadata handling
     saveeffectflag = repo.ui.configbool('experimental',
-                                        'effect-flags')
+                                        'evolution.effect-flags')
 
     tr = repo.transaction('add-obsolescence-marker')
     try: