2 files changed, 9 insertions, 1 deletions
diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index 61c54a77a7..740aa593ac 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+# `counter_cache` requires association class before `attr_readonly`.
+class Post < ActiveRecord::Base; end
+
 class Comment < ActiveRecord::Base
   scope :limit_by, lambda { |l| limit(l) }
   scope :containing_the_letter_e, -> { where("comments.body LIKE '%e%'") }
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index 4b3576fce8..4c8e847354 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -184,14 +184,19 @@ end
 class SpecialPost < Post; end
 
 class StiPost < Post
-  self.abstract_class = true
   has_one :special_comment, class_name: "SpecialComment"
 end
 
+class AbstractStiPost < Post
+  self.abstract_class = true
+end
+
 class SubStiPost < StiPost
   self.table_name = Post.table_name
 end
 
+class SubAbstractStiPost < AbstractStiPost; end
+
 class FirstPost < ActiveRecord::Base
   self.inheritance_column = :disabled
   self.table_name = "posts"