diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -380,6 +380,9 @@ coreconfigitem('logtoprocess', 'command'
 coreconfigitem('logtoprocess', 'develwarn',
     default=None,
 )
+coreconfigitem('logtoprocess', 'uiblocked',
+    default=None,
+)
 coreconfigitem('merge', 'checkunknown',
     default='abort',
 )