<?php

namespace Stripe\Exception;

// TODO: remove this check once we drop support for PHP 5
if (interface_exists(\Throwable::class, false)) {
    /**
     * The base interface for all Stripe exceptions.
     *
     * @package Stripe\Exception
     */
    interface ExceptionInterface extends \Throwable
    {
    }
} else {
    /**
     * The base interface for all Stripe exceptions.
     *
     * @package Stripe\Exception
     */
    // phpcs:disable PSR1.Classes.ClassDeclaration.MultipleClasses
    interface ExceptionInterface
    {
    }
    // phpcs:enable
}

<?php

namespace Stripe\Exception;

// TODO: remove this check once we drop support for PHP 5
if (interface_exists(\Throwable::class)) {
    /**
     * The base interface for all Stripe exceptions.
     *
     * @package Stripe\Exception
     */
    interface ExceptionInterface extends \Throwable
    {
    }
} else {
    /**
     * The base interface for all Stripe exceptions.
     *
     * @package Stripe\Exception
     */
    // phpcs:disable PSR1.Classes.ClassDeclaration.MultipleClasses
    interface ExceptionInterface
    {
    }
    // phpcs:enable
}

--- 
+++ 
@@ -3,7 +3,7 @@
 namespace Stripe\Exception;
 
 // TODO: remove this check once we drop support for PHP 5
-if (interface_exists(\Throwable::class)) {
+if (interface_exists(\Throwable::class, false)) {
     /**
      * The base interface for all Stripe exceptions.
      *
Disable autoloader when checking for `Throwable`
