valentine isn't work with use_strict option in nodejs

[meritt]

I'm trying to require valentine with --use_strict option for nodejs. And i've got an error:

$ node --use_strict v.js 

/Users/simonenko/Sites/projects/mgr/node_modules/valentine/valentine.js:15
    , old = context.v
                   ^
TypeError: Cannot read property 'v' of undefined
    at /Users/simonenko/Sites/projects/mgr/node_modules/valentine/valentine.js:15:20
    at context (/Users/simonenko/Sites/projects/mgr/node_modules/valentine/valentine.js:9:54)
    at Object.<anonymous> (/Users/simonenko/Sites/projects/mgr/node_modules/valentine/valentine.js:12:3)
    at Module._compile (module.js:449:26)
    at Object.Module._extensions..js (module.js:467:10)
    at Module.load (module.js:349:32)
    at Function.Module._load (module.js:305:12)
    at Module.require (module.js:357:17)
    at require (module.js:373:17)
    at Object.<anonymous> (/Users/simonenko/Sites/projects/mgr/v.js:3:9)

v.js file is

var v = require('valentine');
console.log(v);

$ node --version
v0.11.9