diff --git a/CHANGELOG b/CHANGELOG
index 6032314b2..b17e658b4 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix identities "reply-to" and "bcc" fields have a bogus value when left empty (#1487943)
 - Add popup with basic fields selection for addressbook search
 - Case-insensitive matching in autocompletion (#1487933)
 - Added option to force spellchecking before sending a message (#1485458)
diff --git a/program/include/main.inc b/program/include/main.inc
index c312df547..ab529d74b 100644
--- a/program/include/main.inc
+++ b/program/include/main.inc
@@ -1809,6 +1809,10 @@ function rcube_idn_convert($input, $is_utf=false)
 
   $domain = $is_utf ? idn_to_ascii($domain) : idn_to_utf8($domain);
 
+  if ($domain === false) {
+    return '';
+  }
+
   return $at ? $user . '@' . $domain : $domain;
 }