1 files changed, 1 insertions, 1 deletions
diff --git a/lib/gitlab/diff/file.rb b/lib/gitlab/diff/file.rb
index 35581952f4a..0ba23b8ffc7 100644
--- a/lib/gitlab/diff/file.rb
+++ b/lib/gitlab/diff/file.rb
@@ -449,7 +449,7 @@ module Gitlab
       end
 
       def alternate_viewer_class
-        return unless viewer.class == DiffViewer::Renamed
+        return unless viewer.instance_of?(DiffViewer::Renamed)
 
         find_renderable_viewer_class(RICH_VIEWERS) || (DiffViewer::Text if text?)
       end