diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index eef24a7298..146cfa0ffb 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -1871,7 +1871,15 @@ function htmlentities2($myHTML) {
 
 function wp_mail($to, $subject, $message, $headers = '', $more = '') {
 	if ( function_exists('mb_send_mail') )
-		return mb_send_mail($to, $subject, $message, $headers, $more);
+        {
+            if( $headers == '' )
+            {
+                $headers = "MIME-Version: 1.0\r\n" .
+                           "From: " . $to . " <" . $to . ">\r\n" .
+                           "Content-Type: text/plain; charset=\"" . get_settings('blog_charset') . "\"\r\n";
+            }
+            return mb_send_mail($to, $subject, $message, $headers, $more);
+        }
 	else
 		return mail($to, $subject, $message, $headers, $more);
 }