diff --git a/ext/standard/tests/serialize/unserialize_neg_iv_edge_cases.phpt b/ext/standard/tests/serialize/unserialize_neg_iv_edge_cases.phpt
index a3732bde1b7..42b89ee32b7 100644
--- a/ext/standard/tests/serialize/unserialize_neg_iv_edge_cases.phpt
+++ b/ext/standard/tests/serialize/unserialize_neg_iv_edge_cases.phpt
@@ -1,5 +1,7 @@
 --TEST--
 Negative parse_iv2 edge cases
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 8) die("skip 64-bit only"); ?>
 --FILE--
 <?php