--- a/mercurial/phases.py	Wed Mar 01 16:35:57 2017 -0800
+++ b/mercurial/phases.py	Wed Mar 01 15:50:01 2017 -0800
@@ -224,12 +224,8 @@
         """ensure phase information is loaded in the object"""
         if self._phaserevs is None:
             try:
-                if repo.ui.configbool('experimental',
-                                      'nativephaseskillswitch'):
-                    self._computephaserevspure(repo)
-                else:
-                    res = self._getphaserevsnative(repo)
-                    self._phaserevs, self._phasesets = res
+                res = self._getphaserevsnative(repo)
+                self._phaserevs, self._phasesets = res
             except AttributeError:
                 self._computephaserevspure(repo)
 

--- a/tests/test-phases.t	Wed Mar 01 16:35:57 2017 -0800
+++ b/tests/test-phases.t	Wed Mar 01 15:50:01 2017 -0800
@@ -479,12 +479,8 @@
   o  0 public A
   
 
-move changeset forward and backward and test kill switch
+move changeset forward and backward
 
-  $ cat <<EOF >> $HGRCPATH
-  > [experimental]
-  > nativephaseskillswitch = true
-  > EOF
   $ hg phase --draft --force 1::4
   $ hg log -G --template "{rev} {phase} {desc}\n"
   @    7 secret merge B' and E
@@ -505,10 +501,6 @@
   
 test partial failure
 
-  $ cat <<EOF >> $HGRCPATH
-  > [experimental]
-  > nativephaseskillswitch = false
-  > EOF
   $ hg phase --public 7
   $ hg phase --draft '5 or 7'
   cannot move 1 changesets to a higher phase, use --force