diff --git a/framework/base/Widget.php b/framework/base/Widget.php
index d4fcd1d456..700f6139e3 100644
--- a/framework/base/Widget.php
+++ b/framework/base/Widget.php
@@ -90,7 +90,7 @@ class Widget extends Component implements ViewContextInterface
     public static function begin($config = [])
     {
         $config['class'] = get_called_class();
-        /** @var self $widget */
+        /** @var static $widget */
         $widget = Yii::createObject($config);
         self::$stack[] = $widget;
         self::$_resolvedClasses[get_called_class()] = get_class($widget);
@@ -113,7 +113,7 @@ class Widget extends Component implements ViewContextInterface
             $calledClass = self::$_resolvedClasses[get_called_class()] ?? get_called_class();
 
             if (get_class($widget) === $calledClass) {
-                /** @var self $widget */
+                /** @var static $widget */
                 if ($widget->beforeRun()) {
                     $result = $widget->run();
                     $result = $widget->afterRun($result);
diff --git a/framework/captcha/CaptchaValidator.php b/framework/captcha/CaptchaValidator.php
index 641abbd041..b3aa25ea78 100644
--- a/framework/captcha/CaptchaValidator.php
+++ b/framework/captcha/CaptchaValidator.php
@@ -65,7 +65,7 @@ class CaptchaValidator extends Validator
 
     /**
      * Creates the CAPTCHA action object from the route specified by [[captchaAction]].
-     * @return \yii\captcha\CaptchaAction the action object
+     * @return CaptchaAction the action object
      * @throws InvalidConfigException
      */
     public function createCaptchaAction()
@@ -74,6 +74,7 @@ class CaptchaValidator extends Validator
         if ($ca !== false) {
             /** @var \yii\base\Controller $controller */
             list($controller, $actionID) = $ca;
+            /** @var CaptchaAction|null */
             $action = $controller->createAction($actionID);
             if ($action !== null) {
                 return $action;
diff --git a/framework/data/Pagination.php b/framework/data/Pagination.php
index 1524f367a8..6aa53429fb 100644
--- a/framework/data/Pagination.php
+++ b/framework/data/Pagination.php
@@ -139,7 +139,7 @@ class Pagination extends BaseObject implements Linkable
     public $pageSizeLimit = [1, 50];
 
     /**
-     * @var int number of items on each page.
+     * @var int|null number of items on each page.
      * If it is less than 1, it means the page size is infinite, and thus a single page contains all items.
      */
     private $_pageSize;
diff --git a/framework/mail/BaseMailer.php b/framework/mail/BaseMailer.php
index 1703b76fa1..c2893b52ba 100644
--- a/framework/mail/BaseMailer.php
+++ b/framework/mail/BaseMailer.php
@@ -100,7 +100,7 @@ abstract class BaseMailer extends Component implements MailerInterface, ViewCont
     public $fileTransportCallback;
 
     /**
-     * @var \yii\base\View|array view instance or its array configuration.
+     * @var View|array view instance or its array configuration.
      */
     private $_view = [];
     /**