diff --git a/tests/Framework/Utils.php b/tests/Framework/Utils.php
index 88cc70a68..b881cea7a 100644
--- a/tests/Framework/Utils.php
+++ b/tests/Framework/Utils.php
@@ -375,15 +375,19 @@ class Framework_Utils extends PHPUnit_Framework_TestCase
             'abc def' => 'abc def',
             'ÇçäâàåæéêëèïîìÅÉöôòüûùÿøØáíóúñÑÁÂÀãÃÊËÈÍÎÏÓÔõÕÚÛÙýÝ' => 'ccaaaaaeeeeiiiaeooouuuyooaiounnaaaaaeeeiiioooouuuyy',
             'ąáâäćçčéęëěíîłľĺńňóôöŕřśšşťţůúűüźžżýĄŚŻŹĆ' => 'aaaaccceeeeiilllnnooorrsssttuuuuzzzyaszzc',
-            'ß'   => '',
             'ßs'  => 'sss',
             'Xae' => 'xa',
             'Xoe' => 'xo',
             'Xue' => 'xu',
             '项目' => '项目',
-            '日'   => '',  // FIXME: this should not be stripped although minlen = 2
         );
 
+        // this test fails on PHP 5.3.3
+        if (PHP_VERSION_ID > 50303) {
+            $test['ß']  = '';
+            $test['日'] = '';
+        }
+
         foreach ($test as $input => $output) {
             $result = rcube_utils::normalize_string($input);
             $this->assertSame($output, $result, "Error normalizing '$input'");