diff -r 30ab130af221 -r ff955e7b1085 mercurial/repair.py
--- a/mercurial/repair.py	Mon Jun 01 10:28:40 2015 -0700
+++ b/mercurial/repair.py	Fri Feb 06 17:41:24 2015 +0000
@@ -13,7 +13,7 @@
 
 def _bundle(repo, bases, heads, node, suffix, compress=True):
     """create a bundle with the specified revisions as a backup"""
-    usebundle2 = (repo.ui.config('experimental', 'bundle2-exp') and
+    usebundle2 = (repo.ui.config('experimental', 'bundle2-exp', True) and
                   repo.ui.config('experimental', 'strip-bundle2-version'))
     if usebundle2:
         cgversion = repo.ui.config('experimental', 'strip-bundle2-version')