--- trunk/lib/Frey/Web/Button.pm	2008/07/16 14:12:43	141
+++ trunk/lib/Frey/Web/Button.pm	2008/07/16 21:19:53	145
@@ -20,7 +20,7 @@
 use Moose::Role;
 
 # List of callbacks, buttons for now
-has callback => ( is => 'rw', isa => 'HashRef', default => sub {{}} );
+has callback => ( is => 'rw', isa => 'HashRef[CodeRef]', default => sub {{}} );
 has callback_order => ( is => 'rw', isa => 'ArrayRef', default => sub { [] });
 
 sub add_button {