diff --git a/specs/string-literal/misc.php b/specs/string-literal/misc.php
index 3cff0d4a3..fc4713b79 100644
--- a/specs/string-literal/misc.php
+++ b/specs/string-literal/misc.php
@@ -19,6 +19,7 @@
         'prefix' => 'Humbug',
         'whitelist' => [],
         'whitelist-global-constants' => true,
+        'whitelist-global-functions' => true,
     ],
 
     'PHP heredoc as argument' =>  <<<'PHP'