I don't see "Missing @Override annotation" inspection in Idea 12.1.4

I am extending a concrete class and overriding a method in child class without the @Override annotation. When I do 'Inspect Code' it doesn't warn me about the missing @Override annotation. When I go to Settings->Inspections->Class Structure, I don't find the "Missing @Override annotation" inspection. Any idea why? This is my first time using Idea and have been using Eclipse for a while.