diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -34,7 +34,6 @@ from mercurial import (
     error,
     extensions,
     hg,
-    lock,
     merge as mergemod,
     mergeutil,
     obsolete,
@@ -52,8 +51,6 @@ from mercurial import (
     util,
 )
 
-release = lock.release
-
 # The following constants are used throughout the rebase module. The ordering of
 # their values must be maintained.