diff --git a/pylons_app/lib/simplehg.py b/pylons_app/lib/simplehg.py
--- a/pylons_app/lib/simplehg.py
+++ b/pylons_app/lib/simplehg.py
@@ -2,6 +2,8 @@ import os
 from mercurial.hgweb import hgweb
 from mercurial.hgweb.request import wsgiapplication
 from pylons_app.lib.utils import make_ui
+from pylons.controllers.util import abort
+from webob.exc import HTTPNotFound
 class SimpleHg(object):
 
     def __init__(self, application, config):
@@ -12,16 +14,20 @@ class SimpleHg(object):
         if not is_mercurial(environ):
             return self.application(environ, start_response)
         else:
-            #repo_name = environ['PATH_INFO'].replace('/', '')
-            repo_name = environ['PATH_INFO'].split('/')[1]
-            if not environ['PATH_INFO'].endswith == '/':
-                environ['PATH_INFO'] += '/'
-            #environ['SCRIPT_NAME'] = request.path
+            try:
+                repo_name = environ['PATH_INFO'].split('/')[1]
+            except:
+                return HTTPNotFound()(environ, start_response)
+            
+            #since we wrap into hgweb, just reset the path
             environ['PATH_INFO'] = '/'
             self.baseui = make_ui()
             self.basepath = self.baseui.configitems('paths')[0][1].replace('*', '')
             self.repo_path = os.path.join(self.basepath, repo_name)
-            app = wsgiapplication(self._make_app)
+            try:
+                app = wsgiapplication(self._make_app)
+            except Exception as e:
+                return HTTPNotFound()(environ, start_response)
             return app(environ, start_response)            
 
     def _make_app(self):