diff --git a/ext/mbstring/tests/utf_encodings.phpt b/ext/mbstring/tests/utf_encodings.phpt
index 06c35b15465..856f8ff0816 100644
--- a/ext/mbstring/tests/utf_encodings.phpt
+++ b/ext/mbstring/tests/utf_encodings.phpt
@@ -5,6 +5,9 @@ mbstring
 --SKIPIF--
 <?php
 if (getenv("SKIP_SLOW_TESTS")) die("skip slow test");
+if (substr(PHP_OS, 0, 3) === 'WIN' && PHP_INT_SIZE === 4) {
+    die('xfail Fails on 32-bit Windows');
+}
 ?>
 --FILE--
 <?php