diff --git a/tests/output/gh14808.phpt b/tests/output/gh14808.phpt
index 7a3f57ba51c..32addcbc763 100644
--- a/tests/output/gh14808.phpt
+++ b/tests/output/gh14808.phpt
@@ -1,5 +1,7 @@
 --TEST--
 GH-14808 (Unexpected null pointer in Zend/zend_string.h with empty output buffer)
+--EXTENSIONS--
+iconv
 --FILE--
 <?php
 var_dump($args);