diff --git a/framework/base/ErrorHandler.php b/framework/base/ErrorHandler.php
index 9f31bc91e9..69d91693f5 100644
--- a/framework/base/ErrorHandler.php
+++ b/framework/base/ErrorHandler.php
@@ -55,7 +55,7 @@ abstract class ErrorHandler extends Component
     public $silentExitOnException;
 
     /**
-     * @var string Used to reserve memory for fatal error handler.
+     * @var string|null Used to reserve memory for fatal error handler.
      */
     private $_memoryReserve;
     /**
@@ -67,7 +67,7 @@ abstract class ErrorHandler extends Component
      */
     private $_registered = false;
     /**
-     * @var string the current working directory
+     * @var string|null the current working directory
      */
     private $_workingDirectory;
 
diff --git a/framework/base/Model.php b/framework/base/Model.php
index dbb411044a..778421b909 100644
--- a/framework/base/Model.php
+++ b/framework/base/Model.php
@@ -95,11 +95,11 @@ class Model extends Component implements StaticInstanceInterface, IteratorAggreg
     public const EVENT_AFTER_VALIDATE = 'afterValidate';
 
     /**
-     * @var array validation errors (attribute name => array of errors)
+     * @var array|null validation errors (attribute name => array of errors)
      */
     private $_errors;
     /**
-     * @var ArrayObject list of validators
+     * @var ArrayObject|null list of validators
      */
     private $_validators;
     /**
diff --git a/framework/db/BatchQueryResult.php b/framework/db/BatchQueryResult.php
index da0e9cf644..87005ca826 100644
--- a/framework/db/BatchQueryResult.php
+++ b/framework/db/BatchQueryResult.php
@@ -68,11 +68,11 @@ class BatchQueryResult extends Component implements \Iterator
     public $each = false;
 
     /**
-     * @var DataReader the data reader associated with this batch query.
+     * @var DataReader|null the data reader associated with this batch query.
      */
     private $_dataReader;
     /**
-     * @var array the data retrieved in the current batch
+     * @var array|null the data retrieved in the current batch
      */
     private $_batch;
     /**
@@ -80,7 +80,7 @@ class BatchQueryResult extends Component implements \Iterator
      */
     private $_value;
     /**
-     * @var string|int the key for the current iteration
+     * @var string|int|null the key for the current iteration
      */
     private $_key;
 
diff --git a/framework/db/sqlite/Command.php b/framework/db/sqlite/Command.php
index 8bf4c16ec0..23f62d9456 100644
--- a/framework/db/sqlite/Command.php
+++ b/framework/db/sqlite/Command.php
@@ -71,7 +71,9 @@ class Command extends \yii\db\Command
      * or `false` if there's a single statement.
      * @param string $sql
      * @param array $params
-     * @return string[]|false
+     * @return array[]|false
+     *
+     * @phpstan-return list<array{string, array}>|false
      */
     private function splitStatements($sql, $params)
     {
diff --git a/framework/rbac/DbManager.php b/framework/rbac/DbManager.php
index effe55a464..b01986fe40 100644
--- a/framework/rbac/DbManager.php
+++ b/framework/rbac/DbManager.php
@@ -436,7 +436,9 @@ class DbManager extends BaseManager
 
         $items = [];
         foreach ($query->all($this->db) as $row) {
-            $items[$row['name']] = $this->populateItem($row);
+            /** @var Role|Permission */
+            $item = $this->populateItem($row);
+            $items[$row['name']] = $item;
         }
 
         return $items;
diff --git a/framework/rbac/PhpManager.php b/framework/rbac/PhpManager.php
index bfbfb7f02e..bc2842f20a 100644
--- a/framework/rbac/PhpManager.php
+++ b/framework/rbac/PhpManager.php
@@ -325,7 +325,7 @@ class PhpManager extends BaseManager
         $items = [];
 
         foreach ($this->items as $name => $item) {
-            /** @var Item $item */
+            /** @var Role|Permission $item */
             if ($item->type == $type) {
                 $items[$name] = $item;
             }
diff --git a/framework/web/AssetBundle.php b/framework/web/AssetBundle.php
index 5990e4f68d..12e12d90bc 100644
--- a/framework/web/AssetBundle.php
+++ b/framework/web/AssetBundle.php
@@ -149,7 +149,10 @@ class AssetBundle extends BaseObject
      */
     public static function register($view)
     {
-        return $view->registerAssetBundle(get_called_class());
+        /** @var static */
+        $result = $view->registerAssetBundle(get_called_class());
+
+        return $result;
     }
 
     /**