diff --git a/pyramid_formalchemy/views.py b/pyramid_formalchemy/views.py
index efbd174..846b6c9 100644
--- a/pyramid_formalchemy/views.py
+++ b/pyramid_formalchemy/views.py
@@ -73,9 +73,9 @@ class ModelView(object):
         if '_LOCALE_' not in request.cookies:
             locale = get_locale_name(request)
             request.cookies['_LOCALE_'] = locale
-        if '_LOCALE_' not in request.cookies:
+        if '_THEME_' not in request.cookies:
             theme = request.registry.settings.get('default_theme_name', 'smoothness')
-            request.cookies['_LOCALE_'] = theme
+            request.cookies['_THEME_'] = theme
 
     def models(self, **kwargs):
         """Models index page"""