1 files changed, 5 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index aab816899c..140057c186 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -26,6 +26,11 @@ module ActiveRecord
         end
       end
 
+      # Sets the primary ID.
+      def id=(value)
+        write_attribute(self.class.primary_key, value)
+      end
+
       private
         # Handle *= for method_missing.
         def attribute=(attribute_name, value)