diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -603,6 +603,9 @@ coreconfigitem('web', 'cacerts',
 coreconfigitem('web', 'certificate',
     default=None,
 )
+coreconfigitem('web', 'collapse',
+    default=False,
+)
 coreconfigitem('worker', 'backgroundclose',
     default=dynamicdefault,
 )
diff --git a/mercurial/hgweb/hgwebdir_mod.py b/mercurial/hgweb/hgwebdir_mod.py
--- a/mercurial/hgweb/hgwebdir_mod.py
+++ b/mercurial/hgweb/hgwebdir_mod.py
@@ -325,7 +325,7 @@ class hgwebdir(object):
         def rawentries(subdir="", **map):
 
             descend = self.ui.configbool('web', 'descend', True)
-            collapse = self.ui.configbool('web', 'collapse', False)
+            collapse = self.ui.configbool('web', 'collapse')
             seenrepos = set()
             seendirs = set()
             for name, path in self.repos: