diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 127720a3ad..ab546ad540 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -34,6 +34,7 @@ Yii Framework 2 Change Log
 - Bug #3564: Fixed the bug that primary key columns should not take default values from schema (qiangxue)
 - Bug #3567: Fixed the bug that smallint was treated as string for PostgreSQL (qiangxue)
 - Bug #3578: Fixed postgreSQL column type detection, added missing types (MDMunir, cebe)
+- Bug #3591: Fix incomplete obsolete filling in i18n `MessageController::saveMessagesToDb()` (advsm)
 - Bug: Fixed inconsistent return of `\yii\console\Application::runAction()` (samdark)
 - Enh #2264: `CookieCollection::has()` will return false for expired or removed cookies (qiangxue)
 - Enh #2435: `yii\db\IntegrityException` is now thrown on database integrity errors instead of general `yii\db\Exception` (samdark)
diff --git a/framework/console/controllers/MessageController.php b/framework/console/controllers/MessageController.php
index 88e64831e4..22f1b03890 100644
--- a/framework/console/controllers/MessageController.php
+++ b/framework/console/controllers/MessageController.php
@@ -173,7 +173,7 @@ class MessageController extends Controller
 
             if (isset($current[$category])) {
                 $new[$category] = array_diff($msgs, $current[$category]);
-                $obsolete = array_diff($current[$category], $msgs);
+                $obsolete += array_diff($current[$category], $msgs);
             } else {
                 $new[$category] = $msgs;
             }