--- /dev/null
+#!/usr/bin/perl -w
+use Test;
+
+plan tests => 3;
+
+{
+ package Class;
+ sub new {}
+}
+
+{
+ package MouseClass;
+ use Mouse;
+}
+
+
+{
+ package Foo;
+
+ use Mouse;
+
+ has unknown => (
+ is => 'rw',
+ isa => 'HashRef[Unknown]'
+ );
+
+ has class => (
+ is => 'rw',
+ isa => 'HashRef[Class]',
+ );
+
+ has mouse => (
+ is => 'rw',
+ isa => 'HashRef[MouseClass]',
+ );
+}
+
+
+my $obj = Foo->new;
+ok eval { $obj->unknown({}); };
+ok eval { $obj->class({}); };
+ok eval { $obj->mouse({}); };