diff --git a/app/main/views/uploads.py b/app/main/views/uploads.py
index 67b0f606c..e1093f708 100644
--- a/app/main/views/uploads.py
+++ b/app/main/views/uploads.py
@@ -326,7 +326,7 @@ def view_letter_upload_as_preview(service_id, file_id):
 
 @main.route("/services/<uuid:service_id>/upload-letter/send/<uuid:file_id>", methods=['POST'])
 @user_has_permissions('send_messages', restrict_admin_usage=True)
-def send_uploaded_letter(service_id, file_id=None):
+def send_uploaded_letter(service_id, file_id):
     if not (current_service.has_permission('letter') and current_service.has_permission('upload_letters')):
         abort(403)