diff --git a/lib/Catalyst/IOC/Container.pm b/lib/Catalyst/IOC/Container.pm
index 1f007a22f..22f29b8a2 100644
--- a/lib/Catalyst/IOC/Container.pm
+++ b/lib/Catalyst/IOC/Container.pm
@@ -765,6 +765,8 @@ sub expand_component_module {
     return Devel::InnerPackage::list_packages( $module );
 }
 
+__PACKAGE__->meta->make_immutable;
+
 1;
 
 __END__