1 files changed, 5 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index c64e3e6ccf..9c0a292a09 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -232,7 +232,7 @@ module ActiveRecord
       raise ActiveRecordError, "can not update on a new record object" unless persisted?
 
       attributes.each_key do |key|
-        raise ActiveRecordError, "#{key} is marked as readonly" if self.class.readonly_attributes.include?(key.to_s)
+        raise ActiveRecordError, "#{key.to_s} is marked as readonly" if self.class.readonly_attributes.include?(key.to_s)
       end
 
       attributes.each do |k,v|
@@ -405,5 +405,9 @@ module ActiveRecord
       @new_record = false
       id
     end
+
+    def verify_readonly_attribute(name)
+      raise ActiveRecordError, "#{name} is marked as readonly" if self.class.readonly_attributes.include?(name)
+    end
   end
 end