diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index e874486b53..c1739f113a 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Deprecate unused `ActiveRecord::Base.symbolized_base_class`
+    and `ActiveRecord::Base.symbolized_sti_name` without replacement.
+
+    *Yves Senn*
+
 *   Since the `test_help.rb` in Railties now automatically maintains
     your test schema, the `rake db:test:*` tasks are deprecated. This
     doesn't stop you manually running other tasks on your test database
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb
index 7e1e120288..f144d84946 100644
--- a/activerecord/lib/active_record/inheritance.rb
+++ b/activerecord/lib/active_record/inheritance.rb
@@ -45,10 +45,12 @@ module ActiveRecord
       end
 
       def symbolized_base_class
+        ActiveSupport::Deprecation.warn("ActiveRecord::Base.symbolized_base_class is deprecated and will be removed without replacement.")
         @symbolized_base_class ||= base_class.to_s.to_sym
       end
 
       def symbolized_sti_name
+        ActiveSupport::Deprecation.warn("ActiveRecord::Base.symbolized_sti_name is deprecated and will be removed without replacement.")
         @symbolized_sti_name ||= sti_name.present? ? sti_name.to_sym : symbolized_base_class
       end
 
diff --git a/guides/source/4_1_release_notes.md b/guides/source/4_1_release_notes.md
index 0de7860f7d..d2c3ba0493 100644
--- a/guides/source/4_1_release_notes.md
+++ b/guides/source/4_1_release_notes.md
@@ -432,6 +432,9 @@ for detailed changes.
   automatically maintained. See railties release notes. ([Pull
   Request](https://github.com/rails/rails/pull/13528))
 
+* Deprecate unused `ActiveRecord::Base.symbolized_base_class`
+  and `ActiveRecord::Base.symbolized_sti_name` without replacement.
+
 ### Notable changes
 
 * Added `ActiveRecord::Base.to_param` for convenient "pretty" URLs derived from