diff --git a/Zend/tests/concat_003.phpt b/Zend/tests/concat_003.phpt
index 7dbc9ca8c41..07fabd11139 100644
--- a/Zend/tests/concat_003.phpt
+++ b/Zend/tests/concat_003.phpt
@@ -1,5 +1,7 @@
 --TEST--
 Concatenating many small strings should not slowdown allocations
+--SKIPIF--
+<?php if (PHP_DEBUG) { die ("skip debug version is slow"); } ?>
 --INI--
 memory_limit=256m
 --FILE--