diff -r a1d5951efce7 -r 1ad873c3e4a4 hgext/narrow/narrowbundle2.py
--- a/hgext/narrow/narrowbundle2.py	Mon Jun 11 17:06:29 2018 -0400
+++ b/hgext/narrow/narrowbundle2.py	Tue Jun 12 11:31:20 2018 -0400
@@ -408,6 +408,8 @@
                                  topic='widen')
         repo._bookmarks = bmstore
         if chgrpfile:
+            op._widen_uninterr = repo.ui.uninterruptable()
+            op._widen_uninterr.__enter__()
             # presence of _widen_bundle attribute activates widen handler later
             op._widen_bundle = chgrpfile
     # Set the new narrowspec if we're widening. The setnewnarrowpats() method
@@ -455,6 +457,7 @@
                         (undovfs.join(undofile), stringutil.forcebytestr(e)))
 
     # Remove partial backup only if there were no exceptions
+    op._widen_uninterr.__exit__(None, None, None)
     vfs.unlink(chgrpfile)
 
 def setup():