diff --git a/mellon/middleware.py b/mellon/middleware.py
index 78ec782..9bc5ac8 100644
--- a/mellon/middleware.py
+++ b/mellon/middleware.py
@@ -44,7 +44,7 @@ class PassiveAuthenticationMiddleware(MiddlewareMixin):
         if 'no-passive-auth' in request.GET:
             return
         # Skip AJAX requests
-        if request.is_ajax():
+        if request.headers.get('x-requested-with') == 'XMLHttpRequest':
             return
         # Skip AJAX and media/script requests, unless mellon_no_passive is False on the view
         if getattr(view_func, 'mellon_no_passive', True) and 'text/html' not in request.META.get(