diff --git a/mail.php b/mail.php
index bdff951..3f35620 100644
--- a/mail.php
+++ b/mail.php
@@ -1430,7 +1430,7 @@ class mail
     */
   private function decodeHeaders ($header, $content)
   {
-    return substr (iconv_mime_decode ("$header: $content"),
+    return substr (iconv_mime_decode ("$header: $content", 0, "utf-8"),
                    strlen ($header)+2);
   }