diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 4d9bb1620c..e67e20df30 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -152,6 +152,7 @@ Yii Framework 2 Change Log
 - Chg #3956: Flash messages set via `Yii::$app->session->setFlash()` will be removed only if they are accessed (qiangxue)
 - Chg #3989: The default value for `yii\log\FileTarget::$rotateByCopy` now defaults to true to work on windows by default (cebe)
 - Chg #4071: `mail` component renamed to `mailer`, `yii\log\EmailTarget::$mail` renamed to `yii\log\EmailTarget::$mailer` (samdark)
+- Chg #4086: changedAttributes of AfterSaveEvent contain an old values (dizews)
 - Chg: Replaced `clearAll()` and `clearAllAssignments()` in `yii\rbac\ManagerInterface` with `removeAll()`, `removeAllRoles()`, `removeAllPermissions()`, `removeAllRules()` and `removeAllAssignments()` (qiangxue)
 - Chg: Added `$user` as the first parameter of `yii\rbac\Rule::execute()` (qiangxue)
 - Chg: `yii\grid\DataColumn::getDataCellValue()` visibility is now `public` to allow accessing the value from a GridView directly (cebe)
diff --git a/framework/db/ActiveRecord.php b/framework/db/ActiveRecord.php
index 8726a2b4b0..51ccaa4113 100644
--- a/framework/db/ActiveRecord.php
+++ b/framework/db/ActiveRecord.php
@@ -462,8 +462,9 @@ class ActiveRecord extends BaseActiveRecord
             }
         }
 
+        $changedAttributes = array_fill_keys(array_keys($values), null);
         $this->setOldAttributes($values);
-        $this->afterSave(true, $values);
+        $this->afterSave(true, $changedAttributes);
 
         return true;
     }
diff --git a/framework/db/BaseActiveRecord.php b/framework/db/BaseActiveRecord.php
index 076be98908..e61827c156 100644
--- a/framework/db/BaseActiveRecord.php
+++ b/framework/db/BaseActiveRecord.php
@@ -714,10 +714,12 @@ abstract class BaseActiveRecord extends Model implements ActiveRecordInterface
             throw new StaleObjectException('The object being updated is outdated.');
         }
 
+        $changedAttributes = [];
         foreach ($values as $name => $value) {
+            $changedAttributes[$name] = $this->_oldAttributes[$name];
             $this->_oldAttributes[$name] = $this->_attributes[$name];
         }
-        $this->afterSave(false, $values);
+        $this->afterSave(false, $changedAttributes);
 
         return $rows;
     }
@@ -875,7 +877,7 @@ abstract class BaseActiveRecord extends Model implements ActiveRecordInterface
      * the event is triggered.
      * @param boolean $insert whether this method called while inserting a record.
      * If false, it means the method is called while updating a record.
-     * @param array $changedAttributes The attribute values that had changed and were saved.
+     * @param array $changedAttributes The attribute values that had changed and were saved contain old values.
      */
     public function afterSave($insert, $changedAttributes)
     {