Using the undeclared identifier "NSLineBreakByWordWrapping" using xCode 4.3.3

I get "Using an undeclared identifier" NSLineBreakByWordWrapping "on xCode 4.3.3, which does not appear in beta.

This happens by this code:

[text sizeWithFont:font constrainedToSize:textConstraintRect.size lineBreakMode: NSLineBreakByWordWrapping].height);

What do I need to import to solve this problem?

Please, help,