diff --git a/mercurial/extensions.py b/mercurial/extensions.py
--- a/mercurial/extensions.py
+++ b/mercurial/extensions.py
@@ -43,7 +43,8 @@
     'progress',
     'interhg',
     'inotify',
-    'hgcia'
+    'hgcia',
+    'shelve',
 }
 
 def extensions(ui=None):