diff --git a/src/flask_track_usage/__init__.py b/src/flask_track_usage/__init__.py
index fc8d14f..d1e547e 100644
--- a/src/flask_track_usage/__init__.py
+++ b/src/flask_track_usage/__init__.py
@@ -40,7 +40,9 @@
 
 import six
 
-from flask import _request_ctx_stack, g
+# from flask import _request_ctx_stack, g   # _request_ctx_stack is removed since flask-3.0.0
+from flask import g
+from flask.globals import request_ctx
 try:
     from flask_login import current_user
 except Exception:
@@ -109,7 +111,8 @@ def before_request(self):
         """
         Done before every request that is in scope.
         """
-        ctx = _request_ctx_stack.top
+        # ctx = _request_ctx_stack.top
+        ctx = request_ctx
         view_func = self.app.view_functions.get(ctx.request.endpoint)
         if self._type == 'exclude':
             if view_func in self._exclude_views:
@@ -132,7 +135,8 @@ def after_request(self, response):
         :Parameters:
            - `response`: The response on it's way to the client.
         """
-        ctx = _request_ctx_stack.top
+        # ctx = _request_ctx_stack.top
+        ctx = request_ctx
         view_func = self.app.view_functions.get(ctx.request.endpoint)
         if self._type == 'exclude':
             if view_func in self._exclude_views:
diff --git a/src/flask_track_usage/summarization/mongoenginestorage.py b/src/flask_track_usage/summarization/mongoenginestorage.py
index 516950e..c0f686d 100644
--- a/src/flask_track_usage/summarization/mongoenginestorage.py
+++ b/src/flask_track_usage/summarization/mongoenginestorage.py
@@ -42,8 +42,9 @@ def increment(class_dict, src, dest, target_list):
             if dest:
                 doc[dest] = value
         doc.hits += 1
-        doc.transfer += src.content_length
-        doc.save()
+        if src.content_length:
+            doc.transfer += src.content_length
+            doc.save()
 
 
 def generic_get_sum(