3 files changed, 6 insertions, 6 deletions
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 220043c061..6e4f76aa73 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -437,7 +437,7 @@ module ActiveRecord
       def attributes_for_update(attribute_names)
         attribute_names &= self.class.column_names
         attribute_names.delete_if do |name|
-          readonly_attribute?(name)
+          self.class.readonly_attribute?(name)
         end
       end
 
@@ -460,10 +460,6 @@ module ActiveRecord
         end
       end
 
-      def readonly_attribute?(name)
-        self.class.readonly_attributes.include?(name)
-      end
-
       def pk_attribute?(name)
         name == @primary_key
       end
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index a58c5fd48a..b7bc4b3b8e 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -939,7 +939,7 @@ module ActiveRecord
     end
 
     def verify_readonly_attribute(name)
-      raise ActiveRecordError, "#{name} is marked as readonly" if self.class.readonly_attributes.include?(name)
+      raise ActiveRecordError, "#{name} is marked as readonly" if self.class.readonly_attribute?(name)
     end
 
     def _raise_record_not_destroyed
diff --git a/activerecord/lib/active_record/readonly_attributes.rb b/activerecord/lib/active_record/readonly_attributes.rb
index 7bc26993d5..c851ed52c3 100644
--- a/activerecord/lib/active_record/readonly_attributes.rb
+++ b/activerecord/lib/active_record/readonly_attributes.rb
@@ -19,6 +19,10 @@ module ActiveRecord
       def readonly_attributes
         _attr_readonly
       end
+
+      def readonly_attribute?(name) # :nodoc:
+        _attr_readonly.include?(name)
+      end
     end
   end
 end