diff --git a/README.md b/README.md
index 834bb69..c20ed0a 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@ to post it on Twitter.
 
   - PHP 5.3
   - PHP cURL extension
+  - PHP mbstring extension
   - Shaarli >= v0.8.1
 
 ## Installation
diff --git a/shaarli2twitter/shaarli2twitter.php b/shaarli2twitter/shaarli2twitter.php
index beedf37..b527285 100644
--- a/shaarli2twitter/shaarli2twitter.php
+++ b/shaarli2twitter/shaarli2twitter.php
@@ -206,7 +206,7 @@ function replace_placeholder($tweet, $placeholder, $value)
     // Tweets URL have a fixed size due to t.co
     $valueLength = ($placeholder != 'url' && $placeholder != 'permalink') ? strlen($value) : TWEET_URL_LENGTH;
     if ($current + $valueLength > TWEET_LENGTH) {
-        $value = substr($value, 0, TWEET_LENGTH - $current - 3) . '…';
+        $value = mb_strcut($value, 0, TWEET_LENGTH - $current - 3) . '…';
     }
     return str_replace('${'. $placeholder .'}', $value, $tweet);
 }