diff --git a/contrib/dokku-installer.py b/contrib/dokku-installer.py
index 9634951dc..0e103d010 100755
--- a/contrib/dokku-installer.py
+++ b/contrib/dokku-installer.py
@@ -133,10 +133,10 @@ class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
         self.wfile.write(json.dumps({'status': 'ok'}))
 
     def web_admin_user_exists(self):
-    return self.user_exists('web-admin(\d)')
+    return self.user_exists('web-admin(\d+)')
 
     def admin_user_exists(self):
-    return self.user_exists('admin(\d)')
+    return self.user_exists('admin(\d+)')
 
     def user_exists(self, name):
     command = 'dokku ssh-keys:list'