Add check for PCRE UTF-8 support
diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 41ded94..d65f92f 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -500,7 +500,7 @@
 		$str = strip_tags($str);
 		foreach ($trans as $key => $val)
 		{
-			$str = preg_replace('#'.$key.'#ui', $val, $str);
+			$str = preg_replace('#'.$key.'#i'.(UTF8_ENABLED ? 'u' : ''), $val, $str);
 		}
 
 		if ($lowercase === TRUE)