--- a/hgext3rd/evolve/__init__.py	Sat Mar 21 15:04:18 2020 +0100
+++ b/hgext3rd/evolve/__init__.py	Tue Apr 07 19:33:40 2020 +0200
@@ -290,6 +290,7 @@
     state,
     evolvecmd,
     exthelper,
+    headchecking,
     metadata,
     obscache,
     obsexchange,
@@ -344,6 +345,7 @@
 eh.merge(compat.eh)
 eh.merge(cmdrewrite.eh)
 eh.merge(rewind.eh)
+eh.merge(headchecking.eh)
 uisetup = eh.finaluisetup
 extsetup = eh.finalextsetup
 reposetup = eh.finalreposetup