diff --git a/lib/danger/danger_core/dangerfile.rb b/lib/danger/danger_core/dangerfile.rb
index <HASH>..<HASH> 100644
--- a/lib/danger/danger_core/dangerfile.rb
+++ b/lib/danger/danger_core/dangerfile.rb
@@ -250,7 +250,7 @@ module Danger
           danger_id: danger_id
       }
 
-      if env.request_source.respond_to?(:update_pr_by_line!)
+      if env.request_source.respond_to?(:update_pr_by_line!) && ENV["DANGER_MESSAGE_AGGREGATION"]
         env.request_source.update_pr_by_line!(messages: MessageAggregator.aggregate(**report))
       else
         env.request_source.update_pull_request!(
Prevent message aggregation unless DANGER_MESSAGE_AGGREGATION environment variable is set