diff --git a/delivery_carrier_label_postlogistics/postlogistics/web_service.py b/delivery_carrier_label_postlogistics/postlogistics/web_service.py
index 0611c0790c..334533a7db 100644
--- a/delivery_carrier_label_postlogistics/postlogistics/web_service.py
+++ b/delivery_carrier_label_postlogistics/postlogistics/web_service.py
@@ -115,9 +115,9 @@ def _prepare_customer(self, picking):
         }
         logo = company.postlogistics_logo
         if logo:
-            logo_image = Image.open(StringIO(logo.decode('base64')))
+            logo_image = Image.open(StringIO(logo.decode()))
             logo_format = logo_image.format
-            customer['logo'] = logo
+            customer['logo'] = logo.decode()
             customer['logoFormat'] = logo_format
         return customer
 
@@ -423,7 +423,7 @@ def generate_label(self, picking, packages, user_lang=None):
             res['success'] = False
             res['errors'] = [
                 _('Error when communicating with swisspost API: %s') %
-                response.json()
+                response.content.decode("utf-8")
             ]
             return res