diff --git a/kallithea/__init__.py b/kallithea/__init__.py
--- a/kallithea/__init__.py
+++ b/kallithea/__init__.py
@@ -45,6 +45,8 @@ CELERY_EAGER = False
 
 CONFIG = {}
 
+# URL prefix for non repository related links - must start with `/`
+ADMIN_PREFIX = '/_admin'
 URL_SEP = '/'
 
 # Linked module for extensions
diff --git a/kallithea/config/routing.py b/kallithea/config/routing.py
--- a/kallithea/config/routing.py
+++ b/kallithea/config/routing.py
@@ -21,13 +21,10 @@ refer to the routes manual at http://rou
 
 import routes
 
+import kallithea
 from kallithea.lib.utils2 import safe_str
 
 
-# prefix for non repository related links needs to be prefixed with `/`
-ADMIN_PREFIX = '/_admin'
-
-
 class Mapper(routes.Mapper):
     """
     Subclassed Mapper with routematch patched to decode "unicode" str url to
@@ -120,6 +117,7 @@ def make_map(config):
     rmap.connect('issues_url', 'https://bitbucket.org/conservancy/kallithea/issues', _static=True)
 
     # ADMIN REPOSITORY ROUTES
+    ADMIN_PREFIX = kallithea.ADMIN_PREFIX
     with rmap.submapper(path_prefix=ADMIN_PREFIX,
                         controller='admin/repos') as m:
         m.connect("repos", "/repos",
diff --git a/kallithea/model/validators.py b/kallithea/model/validators.py
--- a/kallithea/model/validators.py
+++ b/kallithea/model/validators.py
@@ -28,7 +28,6 @@ from sqlalchemy import func
 from tg.i18n import ugettext as _
 
 import kallithea
-from kallithea.config.routing import ADMIN_PREFIX
 from kallithea.lib.auth import HasPermissionAny, HasRepoGroupPermissionLevel
 from kallithea.lib.compat import OrderedSet
 from kallithea.lib.exceptions import InvalidCloneUriException, LdapImportError
@@ -343,7 +342,7 @@ def ValidRepoName(edit=False, old_data=N
             group_path = value.get('group_path')
             group_name = value.get('group_name')
 
-            if repo_name in [ADMIN_PREFIX, '']:
+            if repo_name in [kallithea.ADMIN_PREFIX, '']:
                 msg = self.message('invalid_repo_name', state, repo=repo_name)
                 raise formencode.Invalid(msg, value, state,
                     error_dict=dict(repo_name=msg)