diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ceb4c4e3..9dc4aeab 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -25,6 +25,7 @@ Avec cette commande, tu clones le sith AE dans le dossier courant.
 Maintenant, faut passer le sith en mode debug dans le fichier de settings personnalisé.
 
     echo "DEBUG=True" > sith/settings_custom.py
+    echo 'EXTERNAL_RES = "False"' >> sith/settings_custom.py
     echo 'SITH_URL = "localhost:8000"' >> sith/settings_custom.py
 
 Enfin, il s'agit de créer la base de donnée de test lors de la première utilisation
diff --git a/core/templates/core/base.jinja b/core/templates/core/base.jinja
index a7951efe..8086ac8d 100644
--- a/core/templates/core/base.jinja
+++ b/core/templates/core/base.jinja
@@ -7,15 +7,18 @@
         <link rel="stylesheet" href="{{ static('core/base.css') }}">
         <link rel="stylesheet" href="{{ static('core/multiple-select.css') }}">
         <link rel="stylesheet" href="{{ static('core/jquery.datetimepicker.min.css') }}">
-        <link rel="stylesheet" href="{{ static('core/js/ui/jquery-ui.min.css') }}">
         <link rel="stylesheet" href="{{ static('ajax_select/css/ajax_select.css') }}">
         <link rel="stylesheet" href="{{ scss('core/style.scss') }}">
-        {% if settings.DEBUG %}
-          <link rel="stylesheet" href="{{ static('core/font-awesome/css/font-awesome.min.css') }}">
-        {% else %}
+        {% if settings.EXTERNAL_RES %}
           <noscript><link rel="stylesheet" href="https://use.fontawesome.com/775817bb35.css"></noscript>
           <script src="https://use.fontawesome.com/c06c9c6980.js"></script>
 
+          <noscript><link rel="stylesheet" type="text/css" href="static('core/js/ui/jquery-ui.min.css')"></noscript>
+          <script src="https://code.jquery.com/ui/1.12.1/jquery-ui.min.js"></script>
+
+        {% else %}
+          <link rel="stylesheet" href="{{ static('core/font-awesome/css/font-awesome.min.css') }}">
+          <link rel="stylesheet" href="{{ static('core/js/ui/jquery-ui.min.css') }}">
         {% endif %}
         {% endblock %}
     </head>
diff --git a/sith/settings.py b/sith/settings.py
index 4570e660..43db370d 100644
--- a/sith/settings.py
+++ b/sith/settings.py
@@ -227,6 +227,9 @@ LOCALE_PATHS = (
 
 PHONENUMBER_DEFAULT_REGION = "FR"
 
+# Whether to use CDNs (True) or local ressources (False) for JS and CSS
+EXTERNAL_RES = True
+
 # Medias
 MEDIA_ROOT = './data/'
 MEDIA_URL = '/data/'