diff --git a/ext/standard/tests/math/bug21523.phpt b/ext/standard/tests/math/bug21523.phpt
index acf0321f178..f1718b0f39d 100644
--- a/ext/standard/tests/math/bug21523.phpt
+++ b/ext/standard/tests/math/bug21523.phpt
@@ -2,6 +2,7 @@
 Bug #21523 (number_format tries to allocate negative amount of memory)
 --FILE--
 <?php // $Id$ vim600:syn=php
+set_time_limit(5);
 
 var_dump(number_format(-2000, 2768));
 echo "OK";