diff --git a/CHANGELOG b/CHANGELOG
index fe342a411..485b720bf 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,8 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix handling of deprecated boolean value of reply_mode option (#1489052)
+
 RELEASE 0.9.0
 -------------
 - Fix display of HTML entities in protected folder name (#1489042)
diff --git a/program/steps/mail/compose.inc b/program/steps/mail/compose.inc
index a35dab27f..415ddeb74 100644
--- a/program/steps/mail/compose.inc
+++ b/program/steps/mail/compose.inc
@@ -562,7 +562,7 @@ function rcmail_prepare_message_body()
     rcmail_write_forward_attachments();
   }
   // reply/edit/draft/forward
-  else if ($compose_mode && ($compose_mode != RCUBE_COMPOSE_REPLY || $RCMAIL->config->get('reply_mode') != -1)) {
+  else if ($compose_mode && ($compose_mode != RCUBE_COMPOSE_REPLY || intval($RCMAIL->config->get('reply_mode')) != -1)) {
     $isHtml = rcmail_compose_editor_mode();
 
     if (!empty($MESSAGE->parts)) {