diff --git a/addons/payment_paypal/controllers/main.py b/addons/payment_paypal/controllers/main.py
index 951799917a4..e14b7d59ca6 100644
--- a/addons/payment_paypal/controllers/main.py
+++ b/addons/payment_paypal/controllers/main.py
@@ -63,7 +63,7 @@ class PaypalController(http.Controller):
 
         Once data is validated, process it. """
         res = False
-        new_post = dict(post, cmd='_notify-validate', charset='utf-8')
+        new_post = dict(post, cmd='_notify-validate', charset='UTF-8')
         reference = post.get('item_number')
         tx = None
         if reference: