Unable to set cart currency in index.php Craft: 2.6.2976
Commerce: 1.2.1341

I want to force currency depending on language (en_us and no). The user should not be allowed to choose.

I've added two currencies 1) EUR - base, 2) NOK.

Putting define('COMMERCE_PAYMENT_CURRENCY', 'EUR'); in the index.php for the english site, and define('COMMERCE_PAYMENT_CURRENCY', 'NOK');in the index.php file for the norwegian site does not work.

The currency is always EUR.

To be clear: Using {{constant('COMMERCE_PAYMENT_CURRENCY')}} does output the correct currency as set in index.php, however the cart is what always remains in EUR (base).

Is this a bug in Commerce?
How do you render the cart? 

Using {{ item.price|commerceCurrency(cart.paymentCurrency,convert=true) }} instead of {{ item.price|commerceCurrency(cart.currency) }} works for me.