diff --git a/bijoe/visualization/views.py b/bijoe/visualization/views.py
index d34dfa2..d96e8b7 100644
--- a/bijoe/visualization/views.py
+++ b/bijoe/visualization/views.py
@@ -234,8 +234,8 @@ class VisualizationsJSONView(MultipleObjectMixin, View):
             known_services = getattr(settings, 'KNOWN_SERVICES', [])
             if known_services:
                 key = None
-                for l in known_services.itervalues():
-                    for service in l.itervalues():
+                for l in known_services.values():
+                    for service in l.values():
                         if service['verif_orig'] == request.GET.get('orig', ''):
                             key = service['secret']
                 if key is None or not signature.check_query(request.META['QUERY_STRING'], key):