diff --git a/ext/mbstring/tests/mbregex_stack_limit.phpt b/ext/mbstring/tests/mbregex_stack_limit.phpt
index 9d0f3acc9d414..a678e3b4f7b38 100644
--- a/ext/mbstring/tests/mbregex_stack_limit.phpt
+++ b/ext/mbstring/tests/mbregex_stack_limit.phpt
@@ -2,6 +2,8 @@
 Test oniguruma stack limit
 --SKIPIF--
 <?php extension_loaded('mbstring') or die('skip mbstring not available'); ?>
+--XFAIL--
+Travis CI has old oniguruma library
 --FILE--
 <?php
 $s = str_repeat(' ', 30000);
diff --git a/ext/mbstring/tests/mbregex_stack_limit2.phpt b/ext/mbstring/tests/mbregex_stack_limit2.phpt
index 12c8c8edab216..3ddff10f8118a 100644
--- a/ext/mbstring/tests/mbregex_stack_limit2.phpt
+++ b/ext/mbstring/tests/mbregex_stack_limit2.phpt
@@ -2,6 +2,8 @@
 Test oniguruma stack limit
 --SKIPIF--
 <?php extension_loaded('mbstring') or die('skip mbstring not available'); ?>
+--XFAIL--
+Travis CI has old oniguruma library
 --FILE--
 <?php
 function mb_trim( $string, $chars = "", $chars_array = array() )