diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 172df9e1eb1f5cf51f7df652415e5248fe63a144..076b5254b1bd0a447336327b0b8b7217158d54c1 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -163,7 +163,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     end
 
     begin
-      MergeRequests::ResolveService.new(project, current_user, params).execute(@merge_request)
+      MergeRequests::ResolveService.new(@merge_request.source_project, current_user, params).execute(@merge_request)
 
       flash[:conflicts_message] = 'Merge conflicts resolved.'
       flash.keep