diff --git a/mercurial/lock.py b/mercurial/lock.py
--- a/mercurial/lock.py
+++ b/mercurial/lock.py
@@ -112,8 +112,7 @@ class lock(object):
         # if locker dead, break lock.  must do this with another lock
         # held, or can race and break valid lock.
         try:
-            l = lock(self.f + '.break')
-            l.trylock()
+            l = lock(self.f + '.break', timeout=0)
             os.unlink(self.f)
             l.release()
         except error.LockError: