diff --git a/product/ERP5/Tool/ContributionTool.py b/product/ERP5/Tool/ContributionTool.py
index d2467895df1dcd8396795b44ae91d15a9424b0d5..7222590967b75fc519ec656526bb91ee0b6d851d 100644
--- a/product/ERP5/Tool/ContributionTool.py
+++ b/product/ERP5/Tool/ContributionTool.py
@@ -176,6 +176,7 @@ class ContributionTool(BaseTool):
         headers = url_file.headers
         if hasattr(headers, 'type'):
           mime_type = headers.type
+          kw['content_type'] = mime_type
       kw['file'] = file
 
     # If the portal_type was provided, we can go faster