--- /dev/null
+package Perl::Critic::Policy::DynamicMoose::RequireMakeImmutable;
+use Moose;
+extends 'Perl::Critic::Policy::DynamicMoose';
+
+use Perl::Critic::Utils ':severities';
+use Perl::Critic::Utils::Moose 'meta_type';
+
+Readonly::Scalar my $EXPL => q{Moose can't optimize itself if classes remain mutable.};
+sub default_severity { $SEVERITY_HIGH }
+
+sub violates_metaclass {
+ my $self = shift;
+ my $meta = shift;
+
+ return if $meta->is_immutable;
+
+ my $desc = "The " . $meta->name . " " . meta_type($meta) . " was not made immutable.";
+
+ return $self->violation($desc, $EXPL);
+}
+
+no Moose;
+
+1;
+
+__END__
+
+=head1 NAME
+
+Perl::Critic::Policy::DynamicMoose::RequireMakeImmutable
+
+=head1 DESCRIPTION
+
+
+=head1 WARNING
+
+B<VERY IMPORTANT:> Most L<Perl::Critic> Policies (including all the ones that
+ship with Perl::Critic> use pure static analysis -- they never compile nor
+execute any of the code that they analyze. However, this policy is very
+different. It actually attempts to compile your code and then compares the
+subroutines mentioned in your code to those found in the symbol table.
+Therefore you should B<not> use this Policy on any code that you do not trust,
+or may have undesirable side-effects at compile-time (such as connecting to the
+network or mutating files).
+
+For this Policy to work, all the modules included in your code must be
+installed locally, and must compile without error.
+
+=head1 AUTHOR
+
+Shawn M Moore, C<sartak@bestpractical.com>
+
+=cut
+
--- /dev/null
+## name Makes immutable
+## failures 0
+## cut
+
+package Class;
+use Moose;
+
+has attr => (
+ is => 'rw',
+);
+
+__PACKAGE__->meta->make_immutable;
+
+#-----------------------------------------------------------------------------
+
+## name Does not make immutable
+## failures 1
+## cut
+
+package Class;
+use Moose;
+
+has attr => (
+ is => 'rw',
+ builder => '_build_attr',
+);
+
+#-----------------------------------------------------------------------------
+
+## name Does not statically make immutable
+## failures 0
+## cut
+
+for (1 .. 5) {
+ my $class = Class::MOP::Class->create("Foo$_");
+ my $method = join '_', "make", "immutable";
+ $class->$method;
+}
+