Woocommerce and stripe plugin

I am using woocommerce 1.6.5.2 and Stripe for woocommerce 1.38

When I go in the checkout page, I get this error:

Fatal error: Call to undefined function is_checkout_pay_page() in /home/shsh/public_html/wp-content/plugins/stripe-for-woocommerce/classes/class-s4wc_gateway.php on line 314

How can I resolve without updating woocommerce ?

via Chebli Mohamed