1 files changed, 10 insertions, 1 deletions
diff --git a/app/controllers/projects/milestones_controller.rb b/app/controllers/projects/milestones_controller.rb
index 569a514b23b..35b65dbce7e 100644
--- a/app/controllers/projects/milestones_controller.rb
+++ b/app/controllers/projects/milestones_controller.rb
@@ -76,7 +76,6 @@ class Projects::MilestonesController < Projects::ApplicationController
     @milestone = Milestones::UpdateService.new(project, current_user, milestone_params).execute(milestone)
 
     respond_to do |format|
-      format.js
       format.html do
         if @milestone.valid?
           redirect_to project_milestone_path(@project, @milestone)
@@ -84,6 +83,16 @@ class Projects::MilestonesController < Projects::ApplicationController
           render :edit
         end
       end
+
+      format.js
+
+      format.json do
+        if @milestone.valid?
+          head :no_content
+        else
+          render json: { errors: @milestone.errors.full_messages }, status: :unprocessable_entity
+        end
+      end
     end
   rescue ActiveRecord::StaleObjectError
     respond_to do |format|