diff --git a/taiga/projects/attachments/api.py b/taiga/projects/attachments/api.py
index d7d3eb3a..d306f27a 100644
--- a/taiga/projects/attachments/api.py
+++ b/taiga/projects/attachments/api.py
@@ -111,7 +111,7 @@ class RawAttachmentView(generics.RetrieveAPIView):
         response['X-Accel-Redirect'] = "/{filepath}".format(filepath=name)
         response['Content-Disposition'] = 'attachment;filename={filename}'.format(
             filename=os.path.basename(name))
-        response['Content-Type'] = mimetypes.guess_type(attachment.url)
+        response['Content-Type'] = mimetypes.guess_type(name)
 
         return response