--- a/mercurial/verify.py
+++ b/mercurial/verify.py
@@ -10,6 +10,13 @@ from i18n import _
 import revlog, mdiff
 
 def verify(repo):
+    lock = repo.lock()
+    try:
+        return _verify(repo)
+    finally:
+        del lock
+
+def _verify(repo):
     filelinkrevs = {}
     filenodes = {}
     changesets = revisions = files = 0
@@ -17,8 +24,6 @@ def verify(repo):
     warnings = [0]
     neededmanifests = {}
 
-    lock = repo.lock()
-
     def err(msg):
         repo.ui.warn(msg + "\n")
         errors[0] += 1