diff --git a/apps/basic/models/User.php b/apps/basic/models/User.php
index 085cda2..af4c42e 100644
--- a/apps/basic/models/User.php
+++ b/apps/basic/models/User.php
@@ -26,14 +26,14 @@ class User extends \yii\base\Object implements \yii\web\IdentityInterface
 
 	public static function findIdentity($id)
 	{
-		return isset(self::$users[$id]) ? new self(self::$users[$id]) : null;
+		return isset(self::$users[$id]) ? new static(self::$users[$id]) : null;
 	}
 
 	public static function findByUsername($username)
 	{
 		foreach (self::$users as $user) {
 			if (strcasecmp($user['username'], $username) === 0) {
-				return new self($user);
+				return new static($user);
 			}
 		}
 		return null;
diff --git a/extensions/jui/Widget.php b/extensions/jui/Widget.php
index 2bbc9e4..8833fbe 100644
--- a/extensions/jui/Widget.php
+++ b/extensions/jui/Widget.php
@@ -66,7 +66,7 @@ class Widget extends \yii\base\Widget
 		/** @var \yii\web\AssetBundle $assetBundle */
 		$assetBundle::register($view);
 		/** @var \yii\web\AssetBundle $themeAsset */
-		$themeAsset = self::$theme;
+		$themeAsset = static::$theme;
 		$themeAsset::register($view);
 
 		$id = $this->options['id'];
diff --git a/framework/yii/BaseYii.php b/framework/yii/BaseYii.php
index f11df7f..ee49c8e 100644
--- a/framework/yii/BaseYii.php
+++ b/framework/yii/BaseYii.php
@@ -147,11 +147,11 @@ class BaseYii
 		$pos = strpos($alias, '/');
 		$root = $pos === false ? $alias : substr($alias, 0, $pos);
 
-		if (isset(self::$aliases[$root])) {
-			if (is_string(self::$aliases[$root])) {
-				return $pos === false ? self::$aliases[$root] : self::$aliases[$root] . substr($alias, $pos);
+		if (isset(static::$aliases[$root])) {
+			if (is_string(static::$aliases[$root])) {
+				return $pos === false ? static::$aliases[$root] : static::$aliases[$root] . substr($alias, $pos);
 			} else {
-				foreach (self::$aliases[$root] as $name => $path) {
+				foreach (static::$aliases[$root] as $name => $path) {
 					if (strpos($alias . '/', $name . '/') === 0) {
 						return $path . substr($alias, strlen($name));
 					}
@@ -178,11 +178,11 @@ class BaseYii
 		$pos = strpos($alias, '/');
 		$root = $pos === false ? $alias : substr($alias, 0, $pos);
 
-		if (isset(self::$aliases[$root])) {
-			if (is_string(self::$aliases[$root])) {
+		if (isset(static::$aliases[$root])) {
+			if (is_string(static::$aliases[$root])) {
 				return $root;
 			} else {
-				foreach (self::$aliases[$root] as $name => $path) {
+				foreach (static::$aliases[$root] as $name => $path) {
 					if (strpos($alias . '/', $name . '/') === 0) {
 						return $name;
 					}
@@ -229,30 +229,30 @@ class BaseYii
 		$root = $pos === false ? $alias : substr($alias, 0, $pos);
 		if ($path !== null) {
 			$path = strncmp($path, '@', 1) ? rtrim($path, '\\/') : static::getAlias($path);
-			if (!isset(self::$aliases[$root])) {
+			if (!isset(static::$aliases[$root])) {
 				if ($pos === false) {
-					self::$aliases[$root] = $path;
+					static::$aliases[$root] = $path;
 				} else {
-					self::$aliases[$root] = [$alias => $path];
+					static::$aliases[$root] = [$alias => $path];
 				}
-			} elseif (is_string(self::$aliases[$root])) {
+			} elseif (is_string(static::$aliases[$root])) {
 				if ($pos === false) {
-					self::$aliases[$root] = $path;
+					static::$aliases[$root] = $path;
 				} else {
-					self::$aliases[$root] = [
+					static::$aliases[$root] = [
 						$alias => $path,
-						$root => self::$aliases[$root],
+						$root => static::$aliases[$root],
 					];
 				}
 			} else {
-				self::$aliases[$root][$alias] = $path;
-				krsort(self::$aliases[$root]);
+				static::$aliases[$root][$alias] = $path;
+				krsort(static::$aliases[$root]);
 			}
-		} elseif (isset(self::$aliases[$root])) {
-			if (is_array(self::$aliases[$root])) {
-				unset(self::$aliases[$root][$alias]);
+		} elseif (isset(static::$aliases[$root])) {
+			if (is_array(static::$aliases[$root])) {
+				unset(static::$aliases[$root][$alias]);
 			} elseif ($pos === false) {
-				unset(self::$aliases[$root]);
+				unset(static::$aliases[$root]);
 			}
 		}
 	}
@@ -278,8 +278,8 @@ class BaseYii
 	 */
 	public static function autoload($className)
 	{
-		if (isset(self::$classMap[$className])) {
-			$classFile = self::$classMap[$className];
+		if (isset(static::$classMap[$className])) {
+			$classFile = static::$classMap[$className];
 			if ($classFile[0] === '@') {
 				$classFile = static::getAlias($classFile);
 			}
@@ -362,8 +362,8 @@ class BaseYii
 
 		$class = ltrim($class, '\\');
 
-		if (isset(self::$objectConfig[$class])) {
-			$config = array_merge(self::$objectConfig[$class], $config);
+		if (isset(static::$objectConfig[$class])) {
+			$config = array_merge(static::$objectConfig[$class], $config);
 		}
 
 		if (($n = func_num_args()) > 1) {
@@ -394,7 +394,7 @@ class BaseYii
 	public static function trace($message, $category = 'application')
 	{
 		if (YII_DEBUG) {
-			self::$app->getLog()->log($message, Logger::LEVEL_TRACE, $category);
+			static::$app->getLog()->log($message, Logger::LEVEL_TRACE, $category);
 		}
 	}
 
@@ -407,7 +407,7 @@ class BaseYii
 	 */
 	public static function error($message, $category = 'application')
 	{
-		self::$app->getLog()->log($message, Logger::LEVEL_ERROR, $category);
+		static::$app->getLog()->log($message, Logger::LEVEL_ERROR, $category);
 	}
 
 	/**
@@ -419,7 +419,7 @@ class BaseYii
 	 */
 	public static function warning($message, $category = 'application')
 	{
-		self::$app->getLog()->log($message, Logger::LEVEL_WARNING, $category);
+		static::$app->getLog()->log($message, Logger::LEVEL_WARNING, $category);
 	}
 
 	/**
@@ -431,7 +431,7 @@ class BaseYii
 	 */
 	public static function info($message, $category = 'application')
 	{
-		self::$app->getLog()->log($message, Logger::LEVEL_INFO, $category);
+		static::$app->getLog()->log($message, Logger::LEVEL_INFO, $category);
 	}
 
 	/**
@@ -453,7 +453,7 @@ class BaseYii
 	 */
 	public static function beginProfile($token, $category = 'application')
 	{
-		self::$app->getLog()->log($token, Logger::LEVEL_PROFILE_BEGIN, $category);
+		static::$app->getLog()->log($token, Logger::LEVEL_PROFILE_BEGIN, $category);
 	}
 
 	/**
@@ -465,7 +465,7 @@ class BaseYii
 	 */
 	public static function endProfile($token, $category = 'application')
 	{
-		self::$app->getLog()->log($token, Logger::LEVEL_PROFILE_END, $category);
+		static::$app->getLog()->log($token, Logger::LEVEL_PROFILE_END, $category);
 	}
 
 	/**
@@ -504,8 +504,8 @@ class BaseYii
 	 */
 	public static function t($category, $message, $params = [], $language = null)
 	{
-		if (self::$app !== null) {
-			return self::$app->getI18n()->translate($category, $message, $params, $language ?: self::$app->language);
+		if (static::$app !== null) {
+			return static::$app->getI18n()->translate($category, $message, $params, $language ?: static::$app->language);
 		} else {
 			$p = [];
 			foreach ((array) $params as $name => $value) {
diff --git a/framework/yii/helpers/BaseInflector.php b/framework/yii/helpers/BaseInflector.php
index deb8239..2f4f01b 100644
--- a/framework/yii/helpers/BaseInflector.php
+++ b/framework/yii/helpers/BaseInflector.php
@@ -280,8 +280,8 @@ class BaseInflector
 	 */
 	public static function pluralize($word)
 	{
-		if (isset(self::$specials[$word])) {
-			return self::$specials[$word];
+		if (isset(static::$specials[$word])) {
+			return static::$specials[$word];
 		}
 		foreach (static::$plurals as $rule => $replacement) {
 			if (preg_match($rule, $word)) {
@@ -298,7 +298,7 @@ class BaseInflector
 	 */
 	public static function singularize($word)
 	{
-		$result = array_search($word, self::$specials, true);
+		$result = array_search($word, static::$specials, true);
 		if ($result !== false) {
 			return $result;
 		}
diff --git a/framework/yii/web/Response.php b/framework/yii/web/Response.php
index 1d77d14..bebd792 100644
--- a/framework/yii/web/Response.php
+++ b/framework/yii/web/Response.php
@@ -254,7 +254,7 @@ class Response extends \yii\base\Response
 			throw new InvalidParamException("The HTTP status code is invalid: $value");
 		}
 		if ($text === null) {
-			$this->statusText = isset(self::$httpStatuses[$this->_statusCode]) ? self::$httpStatuses[$this->_statusCode] : '';
+			$this->statusText = isset(static::$httpStatuses[$this->_statusCode]) ? static::$httpStatuses[$this->_statusCode] : '';
 		} else {
 			$this->statusText = $text;
 		}
diff --git a/tests/unit/TestCase.php b/tests/unit/TestCase.php
index e83605e..c8e5731 100644
--- a/tests/unit/TestCase.php
+++ b/tests/unit/TestCase.php
@@ -32,10 +32,10 @@ abstract class TestCase extends \PHPUnit_Framework_TestCase
 	 */
 	public function getParam($name, $default = null)
 	{
-		if (self::$params === null) {
-			self::$params = require(__DIR__ . '/data/config.php');
+		if (static::$params === null) {
+			static::$params = require(__DIR__ . '/data/config.php');
 		}
-		return isset(self::$params[$name]) ? self::$params[$name] : $default;
+		return isset(static::$params[$name]) ? static::$params[$name] : $default;
 	}
 
 	/**