diff --git a/apps/advanced/common/models/LoginForm.php b/apps/advanced/common/models/LoginForm.php
index 659f01ca81..70c0ffd04e 100644
--- a/apps/advanced/common/models/LoginForm.php
+++ b/apps/advanced/common/models/LoginForm.php
@@ -1,7 +1,6 @@
 <?php
 namespace common\models;
 
-use common\models\User;
 use yii\base\Model;
 use Yii;
 
diff --git a/extensions/apidoc/models/Context.php b/extensions/apidoc/models/Context.php
index 168bc01973..c71f40d30f 100644
--- a/extensions/apidoc/models/Context.php
+++ b/extensions/apidoc/models/Context.php
@@ -9,7 +9,6 @@ namespace yii\apidoc\models;
 
 use phpDocumentor\Reflection\FileReflector;
 use yii\base\Component;
-use yii\base\Exception;
 
 /**
  *
diff --git a/extensions/apidoc/models/FunctionDoc.php b/extensions/apidoc/models/FunctionDoc.php
index 190efbd952..2a482f1d89 100644
--- a/extensions/apidoc/models/FunctionDoc.php
+++ b/extensions/apidoc/models/FunctionDoc.php
@@ -11,7 +11,6 @@ use phpDocumentor\Reflection\DocBlock\Tag\ParamTag;
 use phpDocumentor\Reflection\DocBlock\Tag\PropertyTag;
 use phpDocumentor\Reflection\DocBlock\Tag\ReturnTag;
 use phpDocumentor\Reflection\DocBlock\Tag\ThrowsTag;
-use yii\base\Exception;
 
 /**
  * Represents API documentation information for a `function`.
diff --git a/extensions/apidoc/models/TypeDoc.php b/extensions/apidoc/models/TypeDoc.php
index 739df3cfb0..aad261de11 100644
--- a/extensions/apidoc/models/TypeDoc.php
+++ b/extensions/apidoc/models/TypeDoc.php
@@ -8,7 +8,6 @@
 namespace yii\apidoc\models;
 
 use phpDocumentor\Reflection\DocBlock\Tag\AuthorTag;
-use yii\base\Exception;
 use yii\helpers\StringHelper;
 
 /**
diff --git a/extensions/apidoc/templates/bootstrap/Renderer.php b/extensions/apidoc/templates/bootstrap/Renderer.php
index 9f586199d4..b40f53afa2 100644
--- a/extensions/apidoc/templates/bootstrap/Renderer.php
+++ b/extensions/apidoc/templates/bootstrap/Renderer.php
@@ -11,7 +11,6 @@ use yii\apidoc\models\Context;
 use yii\console\Controller;
 use Yii;
 use yii\helpers\Console;
-use yii\helpers\FileHelper;
 
 /**
  *
diff --git a/extensions/apidoc/templates/bootstrap/assets/AssetBundle.php b/extensions/apidoc/templates/bootstrap/assets/AssetBundle.php
index 0aef5eb654..1ae8021acc 100644
--- a/extensions/apidoc/templates/bootstrap/assets/AssetBundle.php
+++ b/extensions/apidoc/templates/bootstrap/assets/AssetBundle.php
@@ -6,7 +6,6 @@
  */
 
 namespace yii\apidoc\templates\bootstrap\assets;
-use yii\web\JqueryAsset;
 use yii\web\View;
 
 /**
diff --git a/extensions/apidoc/templates/bootstrap/layouts/guide.php b/extensions/apidoc/templates/bootstrap/layouts/guide.php
index 56f2ecc827..6673a974bb 100644
--- a/extensions/apidoc/templates/bootstrap/layouts/guide.php
+++ b/extensions/apidoc/templates/bootstrap/layouts/guide.php
@@ -1,6 +1,5 @@
 <?php
 use yii\apidoc\templates\bootstrap\SideNavWidget;
-use yii\helpers\StringHelper;
 
 /**
  * @var yii\web\View $this
diff --git a/extensions/apidoc/templates/bootstrap/layouts/main.php b/extensions/apidoc/templates/bootstrap/layouts/main.php
index 90708ba986..1e953a62cc 100644
--- a/extensions/apidoc/templates/bootstrap/layouts/main.php
+++ b/extensions/apidoc/templates/bootstrap/layouts/main.php
@@ -1,10 +1,7 @@
 <?php
-use yii\apidoc\templates\bootstrap\SideNavWidget;
 use yii\bootstrap\Nav;
 use yii\bootstrap\NavBar;
 use yii\helpers\Html;
-use yii\helpers\StringHelper;
-use yii\widgets\Menu;
 
 /**
  * @var yii\web\View $this
diff --git a/extensions/apidoc/templates/offline/Renderer.php b/extensions/apidoc/templates/offline/Renderer.php
index 37bf17a2b4..030182bd2e 100644
--- a/extensions/apidoc/templates/offline/Renderer.php
+++ b/extensions/apidoc/templates/offline/Renderer.php
@@ -6,11 +6,7 @@
  */
 
 namespace yii\apidoc\templates\offline;
-use yii\apidoc\models\Context;
-use yii\console\Controller;
 use Yii;
-use yii\helpers\Console;
-use yii\helpers\FileHelper;
 
 /**
  *
diff --git a/extensions/apidoc/templates/offline/assets/AssetBundle.php b/extensions/apidoc/templates/offline/assets/AssetBundle.php
index e8c7024aec..ff3f809d7a 100644
--- a/extensions/apidoc/templates/offline/assets/AssetBundle.php
+++ b/extensions/apidoc/templates/offline/assets/AssetBundle.php
@@ -6,7 +6,6 @@
  */
 
 namespace yii\apidoc\templates\offline\assets;
-use yii\web\JqueryAsset;
 use yii\web\View;
 
 /**
diff --git a/extensions/apidoc/templates/online/Renderer.php b/extensions/apidoc/templates/online/Renderer.php
index 327c8061af..b82765040e 100644
--- a/extensions/apidoc/templates/online/Renderer.php
+++ b/extensions/apidoc/templates/online/Renderer.php
@@ -11,8 +11,6 @@ use yii\apidoc\models\TypeDoc;
 use yii\console\Controller;
 use Yii;
 use yii\helpers\Console;
-use yii\helpers\FileHelper;
-use yii\helpers\StringHelper;
 
 /**
  *
diff --git a/extensions/debug/Module.php b/extensions/debug/Module.php
index 463f5b9e78..55a1068bf2 100644
--- a/extensions/debug/Module.php
+++ b/extensions/debug/Module.php
@@ -11,7 +11,6 @@ use Yii;
 use yii\base\Application;
 use yii\web\View;
 use yii\web\ForbiddenHttpException;
-use yii\helpers\ArrayHelper;
 
 /**
  * The Yii Debug Module provides the debug toolbar and debugger
diff --git a/extensions/mongodb/ActiveRecord.php b/extensions/mongodb/ActiveRecord.php
index 87e7ea0044..ce8ac81747 100644
--- a/extensions/mongodb/ActiveRecord.php
+++ b/extensions/mongodb/ActiveRecord.php
@@ -8,9 +8,7 @@
 namespace yii\mongodb;
 
 use yii\base\InvalidConfigException;
-use yii\base\InvalidParamException;
 use yii\db\BaseActiveRecord;
-use yii\base\UnknownMethodException;
 use yii\db\StaleObjectException;
 use yii\helpers\Inflector;
 use yii\helpers\StringHelper;
diff --git a/extensions/mongodb/Session.php b/extensions/mongodb/Session.php
index 4966a01939..f2ce8b375d 100644
--- a/extensions/mongodb/Session.php
+++ b/extensions/mongodb/Session.php
@@ -8,8 +8,6 @@
 namespace yii\mongodb;
 
 use Yii;
-use yii\mongodb\Connection;
-use yii\mongodb\Query;
 use yii\base\InvalidConfigException;
 
 /**
diff --git a/extensions/redis/Connection.php b/extensions/redis/Connection.php
index b05223d378..b8bbde2149 100644
--- a/extensions/redis/Connection.php
+++ b/extensions/redis/Connection.php
@@ -8,7 +8,6 @@
 namespace yii\redis;
 
 use yii\base\Component;
-use yii\base\InvalidConfigException;
 use yii\db\Exception;
 use yii\helpers\Inflector;
 
diff --git a/extensions/sphinx/IndexSchema.php b/extensions/sphinx/IndexSchema.php
index 2908e82d5d..b93a8f0c7b 100644
--- a/extensions/sphinx/IndexSchema.php
+++ b/extensions/sphinx/IndexSchema.php
@@ -8,7 +8,6 @@
 namespace yii\sphinx;
 
 use yii\base\Object;
-use yii\base\InvalidParamException;
 
 /**
  * IndexSchema represents the metadata of a Sphinx index.
diff --git a/framework/db/ActiveQueryTrait.php b/framework/db/ActiveQueryTrait.php
index c82bd33a20..97eb312158 100644
--- a/framework/db/ActiveQueryTrait.php
+++ b/framework/db/ActiveQueryTrait.php
@@ -6,7 +6,6 @@
  */
 
 namespace yii\db;
-use yii\base\InvalidCallException;
 
 /**
  * ActiveQueryTrait implements the common methods and properties for active record query classes.
diff --git a/framework/helpers/BaseStringHelper.php b/framework/helpers/BaseStringHelper.php
index e99d5a34b3..06fbed66d6 100644
--- a/framework/helpers/BaseStringHelper.php
+++ b/framework/helpers/BaseStringHelper.php
@@ -7,8 +7,6 @@
 
 namespace yii\helpers;
 
-use yii\base\InvalidParamException;
-
 /**
  * BaseStringHelper provides concrete implementation for [[StringHelper]].
  *
diff --git a/tests/unit/data/ar/Customer.php b/tests/unit/data/ar/Customer.php
index 0891b159be..869d9059e1 100644
--- a/tests/unit/data/ar/Customer.php
+++ b/tests/unit/data/ar/Customer.php
@@ -1,7 +1,6 @@
 <?php
 namespace yiiunit\data\ar;
 
-use yii\db\ActiveQuery;
 use yiiunit\framework\db\ActiveRecordTest;
 
 /**
diff --git a/tests/unit/data/ar/mongodb/Customer.php b/tests/unit/data/ar/mongodb/Customer.php
index 01f545f048..01bcb3dade 100644
--- a/tests/unit/data/ar/mongodb/Customer.php
+++ b/tests/unit/data/ar/mongodb/Customer.php
@@ -2,8 +2,6 @@
 
 namespace yiiunit\data\ar\mongodb;
 
-use yii\mongodb\ActiveQuery;
-
 class Customer extends ActiveRecord
 {
 	public static function collectionName()
diff --git a/tests/unit/data/ar/redis/ActiveRecord.php b/tests/unit/data/ar/redis/ActiveRecord.php
index 9f6d526a04..9d5caf0868 100644
--- a/tests/unit/data/ar/redis/ActiveRecord.php
+++ b/tests/unit/data/ar/redis/ActiveRecord.php
@@ -7,8 +7,6 @@
 
 namespace yiiunit\data\ar\redis;
 
-use yii\redis\Connection;
-
 /**
  * ActiveRecord is ...
  *
diff --git a/tests/unit/data/ar/redis/Customer.php b/tests/unit/data/ar/redis/Customer.php
index 8e5a1b8d6c..da5d275b3e 100644
--- a/tests/unit/data/ar/redis/Customer.php
+++ b/tests/unit/data/ar/redis/Customer.php
@@ -2,7 +2,6 @@
 
 namespace yiiunit\data\ar\redis;
 
-use yii\redis\ActiveQuery;
 use yiiunit\extensions\redis\ActiveRecordTest;
 
 class Customer extends ActiveRecord
diff --git a/tests/unit/data/ar/sphinx/ArticleIndex.php b/tests/unit/data/ar/sphinx/ArticleIndex.php
index 66d6bebc15..fa8939b1b4 100644
--- a/tests/unit/data/ar/sphinx/ArticleIndex.php
+++ b/tests/unit/data/ar/sphinx/ArticleIndex.php
@@ -1,8 +1,6 @@
 <?php
 namespace yiiunit\data\ar\sphinx;
 
-use yii\sphinx\ActiveQuery;
-
 class ArticleIndex extends ActiveRecord
 {
 	public $custom_column;
diff --git a/tests/unit/extensions/authclient/BaseOAuthTest.php b/tests/unit/extensions/authclient/BaseOAuthTest.php
index aa5f6b1e5d..025432c162 100644
--- a/tests/unit/extensions/authclient/BaseOAuthTest.php
+++ b/tests/unit/extensions/authclient/BaseOAuthTest.php
@@ -4,7 +4,6 @@ namespace yiiunit\extensions\authclient;
 
 use yii\authclient\signature\PlainText;
 use yii\authclient\OAuthToken;
-use yiiunit\extensions\authclient\TestCase;
 use yii\authclient\BaseOAuth;
 
 class BaseOAuthTest extends TestCase
diff --git a/tests/unit/extensions/authclient/CollectionTest.php b/tests/unit/extensions/authclient/CollectionTest.php
index 3e0f5d0c6f..3c7b3364c7 100644
--- a/tests/unit/extensions/authclient/CollectionTest.php
+++ b/tests/unit/extensions/authclient/CollectionTest.php
@@ -4,7 +4,6 @@ namespace yiiunit\extensions\authclient;
 
 use yii\authclient\Collection;
 use yii\authclient\BaseClient;
-use yiiunit\extensions\authclient\TestCase;
 
 class CollectionTest extends TestCase
 {
diff --git a/tests/unit/extensions/elasticsearch/ActiveRecordTest.php b/tests/unit/extensions/elasticsearch/ActiveRecordTest.php
index 2eb59d1a30..04053fa29b 100644
--- a/tests/unit/extensions/elasticsearch/ActiveRecordTest.php
+++ b/tests/unit/extensions/elasticsearch/ActiveRecordTest.php
@@ -3,10 +3,8 @@
 namespace yiiunit\extensions\elasticsearch;
 
 use yii\base\Event;
-use yii\base\Exception;
 use yii\db\BaseActiveRecord;
 use yii\elasticsearch\Connection;
-use yii\helpers\Json;
 use yiiunit\framework\ar\ActiveRecordTestTrait;
 use yiiunit\data\ar\elasticsearch\ActiveRecord;
 use yiiunit\data\ar\elasticsearch\Customer;
diff --git a/tests/unit/extensions/redis/ActiveRecordTest.php b/tests/unit/extensions/redis/ActiveRecordTest.php
index 294276cf27..5a2102fbbe 100644
--- a/tests/unit/extensions/redis/ActiveRecordTest.php
+++ b/tests/unit/extensions/redis/ActiveRecordTest.php
@@ -2,7 +2,6 @@
 
 namespace yiiunit\extensions\redis;
 
-use yii\redis\ActiveQuery;
 use yiiunit\data\ar\redis\ActiveRecord;
 use yiiunit\data\ar\redis\Customer;
 use yiiunit\data\ar\redis\OrderItem;
diff --git a/tests/unit/extensions/redis/RedisConnectionTest.php b/tests/unit/extensions/redis/RedisConnectionTest.php
index 23ca5124fc..fbc94e3fe1 100644
--- a/tests/unit/extensions/redis/RedisConnectionTest.php
+++ b/tests/unit/extensions/redis/RedisConnectionTest.php
@@ -2,8 +2,6 @@
 
 namespace yiiunit\extensions\redis;
 
-use yii\redis\Connection;
-
 /**
  * @group redis
  */
diff --git a/tests/unit/extensions/sphinx/ExternalActiveRelationTest.php b/tests/unit/extensions/sphinx/ExternalActiveRelationTest.php
index 1740c4203f..3977b26ab0 100644
--- a/tests/unit/extensions/sphinx/ExternalActiveRelationTest.php
+++ b/tests/unit/extensions/sphinx/ExternalActiveRelationTest.php
@@ -6,7 +6,6 @@ use yiiunit\data\ar\sphinx\ActiveRecord;
 use yiiunit\data\ar\ActiveRecord as ActiveRecordDb;
 use yiiunit\data\ar\sphinx\ArticleIndex;
 use yiiunit\data\ar\sphinx\ArticleDb;
-use yiiunit\data\ar\sphinx\TagDb;
 
 /**
  * @group sphinx
diff --git a/tests/unit/extensions/sphinx/SchemaTest.php b/tests/unit/extensions/sphinx/SchemaTest.php
index 2cc3ff9b10..b1a22ab77f 100644
--- a/tests/unit/extensions/sphinx/SchemaTest.php
+++ b/tests/unit/extensions/sphinx/SchemaTest.php
@@ -3,7 +3,6 @@
 namespace yiiunit\extensions\sphinx;
 
 use yii\caching\FileCache;
-use yii\sphinx\Schema;
 
 /**
  * @group sphinx
diff --git a/tests/unit/framework/db/ActiveRecordTest.php b/tests/unit/framework/db/ActiveRecordTest.php
index bf13d2f11a..1eab260b31 100644
--- a/tests/unit/framework/db/ActiveRecordTest.php
+++ b/tests/unit/framework/db/ActiveRecordTest.php
@@ -1,7 +1,6 @@
 <?php
 namespace yiiunit\framework\db;
 
-use yii\db\ActiveQuery;
 use yiiunit\data\ar\ActiveRecord;
 use yiiunit\data\ar\Customer;
 use yiiunit\data\ar\NullValues;
diff --git a/tests/unit/framework/db/QueryBuilderTest.php b/tests/unit/framework/db/QueryBuilderTest.php
index d9f9960920..c278cc0007 100644
--- a/tests/unit/framework/db/QueryBuilderTest.php
+++ b/tests/unit/framework/db/QueryBuilderTest.php
@@ -2,7 +2,6 @@
 
 namespace yiiunit\framework\db;
 
-use yii\db\Query;
 use yii\db\QueryBuilder;
 use yii\db\Schema;
 use yii\db\mysql\QueryBuilder as MysqlQueryBuilder;
diff --git a/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php b/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php
index 3949ba261c..dd48f44342 100644
--- a/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php
+++ b/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php
@@ -1,7 +1,6 @@
 <?php
 namespace yiiunit\framework\db\cubrid;
 
-use yiiunit\data\ar\Customer;
 use yiiunit\framework\db\ActiveRecordTest;
 
 /**
diff --git a/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php b/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php
index 88e950a541..a689e5d6e5 100644
--- a/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php
+++ b/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php
@@ -1,7 +1,6 @@
 <?php
 namespace yiiunit\framework\db\sqlite;
 
-use yiiunit\data\ar\Customer;
 use yiiunit\framework\db\ActiveRecordTest;
 
 /**
diff --git a/tests/unit/framework/log/LoggerTest.php b/tests/unit/framework/log/LoggerTest.php
index 31a4c3b954..97eea7fb9e 100644
--- a/tests/unit/framework/log/LoggerTest.php
+++ b/tests/unit/framework/log/LoggerTest.php
@@ -6,8 +6,6 @@
 namespace yiiunit\framework\log;
 
 
-use yii\debug\LogTarget;
-use yii\log\FileTarget;
 use yii\log\Logger;
 use yiiunit\TestCase;
 
diff --git a/tests/unit/framework/log/TargetTest.php b/tests/unit/framework/log/TargetTest.php
index b4ceb4c1b5..fc7a0a2eee 100644
--- a/tests/unit/framework/log/TargetTest.php
+++ b/tests/unit/framework/log/TargetTest.php
@@ -6,8 +6,6 @@
 namespace yiiunit\framework\log;
 
 
-use yii\debug\LogTarget;
-use yii\log\FileTarget;
 use yii\log\Logger;
 use yii\log\Target;
 use yiiunit\TestCase;