Avoid a warnings

diff --git a/lib/Mouse/Meta/Attribute.pm b/lib/Mouse/Meta/Attribute.pm
index cdea7cb..736c814 100644 (file)
--- a/lib/Mouse/Meta/Attribute.pm
+++ b/lib/Mouse/Meta/Attribute.pm
@@ -34,6 +34,7 @@ my %valid_options = map { $_ => undef } (
   # internally used
   'associated_class',
   'associated_methods',
+  '__METACLASS__',
 
   # Moose defines, but Mouse doesn't
   #'definition_context',