lib/Exception/ExceptionInterface.php

@@ -2,13 +2,25 @@
 
 namespace Stripe\Exception;
 
-/**
- * The base interface for all Stripe exceptions.
- *
- * @package Stripe\Exception
- *
- * @todo extend \Throwable once we drop support for PHP 5.6
- */
-interface ExceptionInterface // extends \Throwable
-{
+// 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
 }