diff --git a/app/controllers/compare_controller.rb b/app/controllers/compare_controller.rb
index a67dbd92b..e5e61598e 100644
--- a/app/controllers/compare_controller.rb
+++ b/app/controllers/compare_controller.rb
@@ -7,7 +7,7 @@ class CompareController < ApplicationController
 
   def show
     base_ref = Addressable::URI.unescape(params[:base])
-    @ref = head_ref = Addressable::URI.unescape(params[:head])
+    @ref = head_ref = Addressable::URI.unescape(params[:head]&.split('.json')[0])
     @compare_result = Gitea::Repository::Commits::CompareService.call(@owner.login, @project.identifier, base_ref, head_ref)
 
     # render json: @compare_result