diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -917,9 +917,8 @@ class localrepository(repo.repository):
 
         The callback will be executed on lock release."""
         l = self._lockref and self._lockref()
-        assert l is not None
-        assert l.held
-        l.postreleasehooks.append(callback)
+        if l:
+            l.postreleasehooks.append(callback)
 
     def lock(self, wait=True):
         '''Lock the repository store (.hg/store) and return a weak reference