diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md
index 556c2544ff36cebcdbaf107386e19630a6c6f058..bff60efc33ddb504ccaccf40384629217b7c35a4 100644
--- a/guides/source/active_record_basics.md
+++ b/guides/source/active_record_basics.md
@@ -188,11 +188,11 @@ end
 ```
 
 It's also possible to override the column that should be used as the table's
-primary key using the `ActiveRecord::Base.set_primary_key` method:
+primary key using the `ActiveRecord::Base.primary_key=` method:
 
 ```ruby
 class Product < ActiveRecord::Base
-  set_primary_key "product_id"
+  self.primary_key = "product_id"
 end
 ```