diff --git a/seahub/urls.py b/seahub/urls.py
index d1a8100cc8..f4864d3598 100644
--- a/seahub/urls.py
+++ b/seahub/urls.py
@@ -503,7 +503,8 @@ urlpatterns = [
     url(r'^invite/', include('seahub.invitations.urls', app_name='invitations', namespace='invitations')),
     url(r'^terms/', include('termsandconditions.urls')),
     url(r'^published/', include('seahub.wiki.urls', app_name='wiki', namespace='wiki')),
-    url(r'^wikis/', include('seahub.wiki.urls', app_name='wiki', namespace='wiki')),
+    # Must specify a namespace if specifying app_name.
+    url(r'^wikis/', include('seahub.wiki.urls', app_name='wiki', namespace='wiki-unused')),
     url(r'^drafts/', include('seahub.drafts.urls', app_name='drafts', namespace='drafts')),
 
     ## admin::address book