diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index d3edcf3cdb..451104106c 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -466,7 +466,7 @@ module ActiveRecord
       @connection.respond_to?(:reverting) && @connection.reverting
     end
 
-    class ReversibleBlockHelper < Struct.new(:reverting)
+    class ReversibleBlockHelper < Struct.new(:reverting) # :nodoc:
       def up
         yield unless reverting
       end