diff --git a/app/controllers/attachments_controller.rb b/app/controllers/attachments_controller.rb
index b4628bff1..fbe79f27d 100644
--- a/app/controllers/attachments_controller.rb
+++ b/app/controllers/attachments_controller.rb
@@ -49,7 +49,8 @@ class AttachmentsController < ApplicationController
         url.gsub!(url.split("/")[-1], '')
         Rails.logger.info("url===#{url}")
         Rails.logger.info(filepath)
-        request_url = [domain, api_url, URI.encode(url), URI.escape(filepath), "?ref=#{URI.escape(ref.split('ref=')[1])}&access_token=#{User.where(admin: true).take&.gitea_token}"].join
+        ref = ref.blank? ? "" : URI.escape(ref.split('ref=')[1])
+        request_url = [domain, api_url, URI.encode(url), URI.escape(filepath), "?ref=#{ref}&access_token=#{User.where(admin: true).take&.gitea_token}"].join
         Rails.logger.info("request_url===#{request_url}")
         file = Util.download_file(request_url, tmp_path)
         filename = filepath