Commerce subscription tests don't run

In my attempt to understand what this module does I tried to run the tests. I installed a fresh Commerce Kickstart, enabled all required modules by hand, then enabled Commerce Subscription. Running the tests dies on the very first one apparently because entity_get_controller() doesn't have access to the subscription entity but I'm not sure why.

class CommerceSubscriptionEntityTestCase extends CommerceSubscriptionTestCase {

  public static function getInfo() {
    return array(
      'name' => 'Subscription entity integration',
      'description' => 'Tests the subscription entity integration.',
      'group' => 'Commerce Subscription',
    );
  }

  function testEntityMetadataWrappers() {
    // The following line dies
    $membership = commerce_subscription_new('membership');