diff --git a/inc/html.php b/inc/html.php
index 148d111aa1ab0a55e7c27eeb0205eaf3049d5ba5..c4c3348926afa4c056a25a8b1b26a89d8dfa8441 100644
--- a/inc/html.php
+++ b/inc/html.php
@@ -267,7 +267,7 @@ function html_hilight($html,$regex){
   $regex = preg_replace('![\[\]()/\\\\?\.+*]+!','',$regex);
 
   if ($regex === '') return $html;
-  $html = preg_replace_callback("/((<[^>]*)|$regex)/i",'html_hilight_callback',$html);
+  $html = preg_replace_callback("/((<[^>]*)|$regex)/ui",'html_hilight_callback',$html);
   return $html;
 }