diff --git a/UPGRADE.md b/UPGRADE.md
index 56a8f8f7a6b..ac0303675ba 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -1,5 +1,19 @@
 # Upgrade to 3.0
 
+## BC Break: Removed support for entity namespace aliases
+
+The support for namespace aliases has been removed.
+Please migrate to using `::class` for referencing classes.
+
+These methods have been removed:
+
+ * `Doctrine\ORM\Configuration::addEntityNamespace()`
+ * `Doctrine\ORM\Configuration::getEntityNamespace()`
+ * `Doctrine\ORM\Configuration::setEntityNamespaces()`
+ * `Doctrine\ORM\Configuration::getEntityNamespaces()`
+ * `Doctrine\ORM\Mapping\AbstractClassMetadataFactory::getFqcnFromAlias()`
+ * `Doctrine\ORM\ORMException::unknownEntityNamespace()`
+
 ## BC Break: Removed same-namespace class name resolution
 
 Support for same-namespace class name resolution in mappings has been removed.
diff --git a/docs/en/reference/dql-doctrine-query-language.rst b/docs/en/reference/dql-doctrine-query-language.rst
index fdd1924e943..c7149647991 100644
--- a/docs/en/reference/dql-doctrine-query-language.rst
+++ b/docs/en/reference/dql-doctrine-query-language.rst
@@ -1462,7 +1462,6 @@ Terminals
 
 -  identifier (name, email, ...) must match ``[a-z_][a-z0-9_]*``
 -  fully_qualified_name (Doctrine\Tests\Models\CMS\CmsUser) matches PHP's fully qualified class names
--  aliased_name (CMS:CmsUser) uses two identifiers, one for the namespace alias and one for the class inside it
 -  string ('foo', 'bar''s house', '%ninja%', ...)
 -  char ('/', '\\', ' ', ...)
 -  integer (-1, 0, 1, 34, ...)
@@ -1497,7 +1496,7 @@ Identifiers
     AliasIdentificationVariable :: = identifier
 
     /* identifier that must be a class name (the "User" of "FROM User u"), possibly as a fully qualified class name or namespace-aliased */
-    AbstractSchemaName ::= fully_qualified_name | aliased_name | identifier
+    AbstractSchemaName ::= fully_qualified_name | identifier
 
     /* Alias ResultVariable declaration (the "total" of "COUNT(*) AS total") */
     AliasResultVariable = identifier
diff --git a/lib/Doctrine/ORM/AbstractQuery.php b/lib/Doctrine/ORM/AbstractQuery.php
index 7fd9b099f7c..5800df88321 100644
--- a/lib/Doctrine/ORM/AbstractQuery.php
+++ b/lib/Doctrine/ORM/AbstractQuery.php
@@ -405,7 +405,6 @@ public function processParameterValue($value)
      */
     public function setResultSetMapping(Query\ResultSetMapping $rsm)
     {
-        $this->translateNamespaces($rsm);
         $this->resultSetMapping = $rsm;
 
         return $this;
@@ -421,19 +420,6 @@ protected function getResultSetMapping()
         return $this->resultSetMapping;
     }
 
-    /**
-     * Allows to translate entity namespaces to full qualified names.
-     */
-    private function translateNamespaces(Query\ResultSetMapping $rsm)
-    {
-        $translate = function ($alias) {
-            return $this->em->getClassMetadata($alias)->getClassName();
-        };
-
-        $rsm->aliasMap         = array_map($translate, $rsm->aliasMap);
-        $rsm->declaringClasses = array_map($translate, $rsm->declaringClasses);
-    }
-
     /**
      * Set a cache profile for hydration caching.
      *
diff --git a/lib/Doctrine/ORM/Configuration.php b/lib/Doctrine/ORM/Configuration.php
index d98da5e323d..f8ba229db92 100644
--- a/lib/Doctrine/ORM/Configuration.php
+++ b/lib/Doctrine/ORM/Configuration.php
@@ -62,11 +62,6 @@ class Configuration extends DBALConfiguration
      */
     private $metadataCache;
 
-    /**
-     * @var string[] indexed by alias
-     */
-    private $entityNamespaces = [];
-
     /**
      * @var string[] of DQL, indexed by query name
      */
@@ -211,48 +206,6 @@ public function newDefaultAnnotationDriver(array $paths = []) : AnnotationDriver
         return new AnnotationDriver($reader, $paths);
     }
 
-    /**
-     * Adds a namespace under a certain alias.
-     */
-    public function addEntityNamespace(string $alias, string $namespace) : void
-    {
-        $this->entityNamespaces[$alias] = $namespace;
-    }
-
-    /**
-     * Resolves a registered namespace alias to the full namespace.
-     *
-     * @throws ORMException
-     */
-    public function getEntityNamespace(string $entityNamespaceAlias) : string
-    {
-        if (! isset($this->entityNamespaces[$entityNamespaceAlias])) {
-            throw ORMException::unknownEntityNamespace($entityNamespaceAlias);
-        }
-
-        return trim($this->entityNamespaces[$entityNamespaceAlias], '\\');
-    }
-
-    /**
-     * Sets the entity alias map.
-     *
-     * @param string[] $entityNamespaces indexed by namespace alias
-     */
-    public function setEntityNamespaces(array $entityNamespaces) : void
-    {
-        $this->entityNamespaces = $entityNamespaces;
-    }
-
-    /**
-     * Retrieves the list of registered entity namespace aliases.
-     *
-     * @return string[] indexed by namespace alias
-     */
-    public function getEntityNamespaces() : array
-    {
-        return $this->entityNamespaces;
-    }
-
     /**
      * Gets the cache driver implementation that is used for the mapping metadata.
      */
diff --git a/lib/Doctrine/ORM/Mapping/AbstractClassMetadataFactory.php b/lib/Doctrine/ORM/Mapping/AbstractClassMetadataFactory.php
index 66537fc0ed0..94b0ef8fab9 100644
--- a/lib/Doctrine/ORM/Mapping/AbstractClassMetadataFactory.php
+++ b/lib/Doctrine/ORM/Mapping/AbstractClassMetadataFactory.php
@@ -307,12 +307,6 @@ protected function onNotFoundMetadata(
 
     private function normalizeClassName(string $className) : string
     {
-        if (strpos($className, ':') !== false) {
-            [$namespaceAlias, $simpleClassName] = explode(':', $className, 2);
-
-            return $this->getFqcnFromAlias($namespaceAlias, $simpleClassName);
-        }
-
         return StaticClassNameConverter::getRealClass($className);
     }
 
@@ -322,14 +316,6 @@ private function normalizeClassName(string $className) : string
      */
     abstract protected function initialize() : void;
 
-    /**
-     * Gets the fully qualified class-name from the namespace alias.
-     *
-     * @param string $namespaceAlias
-     * @param string $simpleClassName
-     */
-    abstract protected function getFqcnFromAlias($namespaceAlias, $simpleClassName) : string;
-
     /**
      * Returns the mapping driver implementation.
      */
diff --git a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
index 3d010316a7a..b9d82d3b29a 100644
--- a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
+++ b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
@@ -518,14 +518,6 @@ private function completeFieldIdentifierGeneratorMapping(FieldMetadata $field)
         }
     }
 
-    /**
-     * {@inheritDoc}
-     */
-    protected function getFqcnFromAlias($namespaceAlias, $simpleClassName) : string
-    {
-        return $this->em->getConfiguration()->getEntityNamespace($namespaceAlias) . '\\' . $simpleClassName;
-    }
-
     /**
      * {@inheritDoc}
      */
diff --git a/lib/Doctrine/ORM/ORMException.php b/lib/Doctrine/ORM/ORMException.php
index bdc5c88d899..ff5609e5283 100644
--- a/lib/Doctrine/ORM/ORMException.php
+++ b/lib/Doctrine/ORM/ORMException.php
@@ -252,16 +252,6 @@ public static function proxyClassesAlwaysRegenerating()
         return new self('Proxy Classes are always regenerating.');
     }
 
-    /**
-     * @param string $entityNamespaceAlias
-     *
-     * @return ORMException
-     */
-    public static function unknownEntityNamespace($entityNamespaceAlias)
-    {
-        return new self(sprintf("Unknown Entity namespace alias '%s'.", $entityNamespaceAlias));
-    }
-
     /**
      * @param string $className
      *
diff --git a/lib/Doctrine/ORM/Query/Parser.php b/lib/Doctrine/ORM/Query/Parser.php
index 9de727cebca..3fecc8111b1 100644
--- a/lib/Doctrine/ORM/Query/Parser.php
+++ b/lib/Doctrine/ORM/Query/Parser.php
@@ -914,7 +914,7 @@ public function AliasIdentificationVariable()
     }
 
     /**
-     * AbstractSchemaName ::= fully_qualified_name | aliased_name | identifier
+     * AbstractSchemaName ::= fully_qualified_name | identifier
      *
      * @return string
      */
@@ -923,20 +923,12 @@ public function AbstractSchemaName()
         if ($this->lexer->isNextToken(Lexer::T_FULLY_QUALIFIED_NAME)) {
             $this->match(Lexer::T_FULLY_QUALIFIED_NAME);
 
-            $schemaName = $this->lexer->token['value'];
-        } elseif ($this->lexer->isNextToken(Lexer::T_IDENTIFIER)) {
-            $this->match(Lexer::T_IDENTIFIER);
-
-            $schemaName = $this->lexer->token['value'];
-        } else {
-            $this->match(Lexer::T_ALIASED_NAME);
-
-            list($namespaceAlias, $simpleClassName) = explode(':', $this->lexer->token['value']);
-
-            $schemaName = $this->em->getConfiguration()->getEntityNamespace($namespaceAlias) . '\\' . $simpleClassName;
+            return $this->lexer->token['value'];
         }
 
-        return $schemaName;
+        $this->match(Lexer::T_IDENTIFIER);
+
+        return $this->lexer->token['value'];
     }
 
     /**
diff --git a/tests/Doctrine/Tests/ORM/ConfigurationTest.php b/tests/Doctrine/Tests/ORM/ConfigurationTest.php
index 4123627faac..a1316022d0c 100644
--- a/tests/Doctrine/Tests/ORM/ConfigurationTest.php
+++ b/tests/Doctrine/Tests/ORM/ConfigurationTest.php
@@ -66,17 +66,6 @@ public function testNewDefaultAnnotationDriver()
         self::assertInstanceOf(AnnotationNamespace\PrePersist::class, $annotation);
     }
 
-    public function testSetGetEntityNamespace()
-    {
-        $this->configuration->addEntityNamespace('TestNamespace', __NAMESPACE__);
-        self::assertSame(__NAMESPACE__, $this->configuration->getEntityNamespace('TestNamespace'));
-        $namespaces = ['OtherNamespace' => __NAMESPACE__];
-        $this->configuration->setEntityNamespaces($namespaces);
-        self::assertSame($namespaces, $this->configuration->getEntityNamespaces());
-        $this->expectException(ORMException::class);
-        $this->configuration->getEntityNamespace('NonExistingNamespace');
-    }
-
     public function testSetGetQueryCacheImpl()
     {
         self::assertNull($this->configuration->getQueryCacheImpl()); // defaults
diff --git a/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryCriteriaTest.php b/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryCriteriaTest.php
index 790adcfac8b..92e38e38eac 100644
--- a/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryCriteriaTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryCriteriaTest.php
@@ -23,14 +23,6 @@ protected function setUp()
         parent::setUp();
     }
 
-    public function tearDown()
-    {
-        if ($this->em) {
-            $this->em->getConfiguration()->setEntityNamespaces([]);
-        }
-        parent::tearDown();
-    }
-
     public function loadFixture()
     {
         $today = new DateTimeModel();
diff --git a/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryTest.php b/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryTest.php
index b8e45a5f872..3703c0df9bd 100644
--- a/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/EntityRepositoryTest.php
@@ -34,14 +34,6 @@ protected function setUp()
         parent::setUp();
     }
 
-    public function tearDown()
-    {
-        if ($this->em) {
-            $this->em->getConfiguration()->setEntityNamespaces([]);
-        }
-        parent::tearDown();
-    }
-
     public function loadFixture()
     {
         $user = new CmsUser;
@@ -261,19 +253,6 @@ public function testFindAll()
         self::assertCount(4, $users);
     }
 
-    public function testFindByAlias()
-    {
-        $user1Id = $this->loadFixture();
-        $repos = $this->em->getRepository(CmsUser::class);
-
-        $this->em->getConfiguration()->addEntityNamespace('CMS', 'Doctrine\Tests\Models\CMS');
-
-        $repos = $this->em->getRepository('CMS:CmsUser');
-
-        $users = $repos->findAll();
-        self::assertCount(4, $users);
-    }
-
     public function testCount()
     {
         $this->loadFixture();
@@ -647,22 +626,6 @@ public function testSetDefaultRepositoryInvalidClassError()
         $this->em->getConfiguration()->setDefaultRepositoryClassName(DDC753InvalidRepository::class);
     }
 
-    /**
-     * @group DDC-3257
-     */
-    public function testSingleRepositoryInstanceForDifferentEntityAliases()
-    {
-        $config = $this->em->getConfiguration();
-
-        $config->addEntityNamespace('Aliased', 'Doctrine\Tests\Models\CMS');
-        $config->addEntityNamespace('AliasedAgain', 'Doctrine\Tests\Models\CMS');
-
-        $repository = $this->em->getRepository(CmsUser::class);
-
-        self::assertSame($repository, $this->em->getRepository('Aliased:CmsUser'));
-        self::assertSame($repository, $this->em->getRepository('AliasedAgain:CmsUser'));
-    }
-
     /**
      * @group DDC-3257
      */
diff --git a/tests/Doctrine/Tests/ORM/Functional/NewOperatorTest.php b/tests/Doctrine/Tests/ORM/Functional/NewOperatorTest.php
index dd846732730..eb14c692e19 100644
--- a/tests/Doctrine/Tests/ORM/Functional/NewOperatorTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/NewOperatorTest.php
@@ -210,62 +210,6 @@ public function testShouldAssumeFromEntityNamespaceWhenNotGiven()
         self::assertInstanceOf(CmsUserDTO::class, $result[2]);
     }
 
-    public function testShouldSupportFromEntityNamespaceAlias()
-    {
-        $dql = "
-            SELECT
-                new CmsUserDTO(u.name, e.email, a.city)
-            FROM
-                cms:CmsUser u
-            JOIN
-                u.email e
-            JOIN
-                u.address a
-            ORDER BY
-                u.name";
-
-
-        $this->em->getConfiguration()
-            ->addEntityNamespace('cms', 'Doctrine\Tests\Models\CMS');
-
-        $query  = $this->em->createQuery($dql);
-        $result = $query->getResult();
-
-        self::assertCount(3, $result);
-
-        self::assertInstanceOf(CmsUserDTO::class, $result[0]);
-        self::assertInstanceOf(CmsUserDTO::class, $result[1]);
-        self::assertInstanceOf(CmsUserDTO::class, $result[2]);
-    }
-
-    public function testShouldSupportValueObjectNamespaceAlias()
-    {
-        $dql = "
-            SELECT
-                new cms:CmsUserDTO(u.name, e.email, a.city)
-            FROM
-                cms:CmsUser u
-            JOIN
-                u.email e
-            JOIN
-                u.address a
-            ORDER BY
-                u.name";
-
-
-        $this->em->getConfiguration()
-            ->addEntityNamespace('cms', 'Doctrine\Tests\Models\CMS');
-
-        $query  = $this->em->createQuery($dql);
-        $result = $query->getResult();
-
-        self::assertCount(3, $result);
-
-        self::assertInstanceOf(CmsUserDTO::class, $result[0]);
-        self::assertInstanceOf(CmsUserDTO::class, $result[1]);
-        self::assertInstanceOf(CmsUserDTO::class, $result[2]);
-    }
-
     public function testShouldSupportLiteralExpression()
     {
         $dql = "
diff --git a/tests/Doctrine/Tests/ORM/Functional/PersistentCollectionCriteriaTest.php b/tests/Doctrine/Tests/ORM/Functional/PersistentCollectionCriteriaTest.php
index d6144d6bae0..0991099b245 100644
--- a/tests/Doctrine/Tests/ORM/Functional/PersistentCollectionCriteriaTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/PersistentCollectionCriteriaTest.php
@@ -26,14 +26,6 @@ protected function setUp()
         parent::setUp();
     }
 
-    public function tearDown()
-    {
-        if ($this->em) {
-            $this->em->getConfiguration()->setEntityNamespaces([]);
-        }
-        parent::tearDown();
-    }
-
     public function loadTweetFixture()
     {
         $author = new TweetUser();
diff --git a/tests/Doctrine/Tests/ORM/Functional/QueryTest.php b/tests/Doctrine/Tests/ORM/Functional/QueryTest.php
index 63e0c39b853..ae6de67fdc1 100644
--- a/tests/Doctrine/Tests/ORM/Functional/QueryTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/QueryTest.php
@@ -412,23 +412,6 @@ public function testModifiedLimitQuery()
                   ->getScalarResult();
     }
 
-    public function testSupportsQueriesWithEntityNamespaces()
-    {
-        $this->em->getConfiguration()->addEntityNamespace('CMS', 'Doctrine\Tests\Models\CMS');
-
-        try {
-            $query = $this->em->createQuery('UPDATE CMS:CmsUser u SET u.name = ?1');
-
-            self::assertEquals('UPDATE "cms_users" SET "name" = ?', $query->getSQL());
-
-            $query->free();
-        } catch (\Exception $e) {
-            $this->fail($e->getMessage());
-        }
-
-        $this->em->getConfiguration()->setEntityNamespaces([]);
-    }
-
     /**
      * @group DDC-604
      */
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2256Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2256Test.php
deleted file mode 100644
index 4860a2f4d9a..00000000000
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2256Test.php
+++ /dev/null
@@ -1,120 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Doctrine\Tests\ORM\Functional\Ticket;
-
-use Doctrine\ORM\Annotation as ORM;
-use Doctrine\ORM\Query\ResultSetMapping;
-use Doctrine\ORM\Query\ResultSetMappingBuilder;
-
-/**
- * @group DDC-2256
- */
-class DDC2256Test extends \Doctrine\Tests\OrmFunctionalTestCase
-{
-    protected function setUp()
-    {
-        parent::setUp();
-
-        $this->schemaTool->createSchema(
-            [
-                $this->em->getClassMetadata(DDC2256User::class),
-                $this->em->getClassMetadata(DDC2256Group::class)
-            ]
-        );
-    }
-
-    public function testIssue()
-    {
-        $config = $this->em->getConfiguration();
-        $config->addEntityNamespace('MyNamespace', __NAMESPACE__);
-
-        $user = new DDC2256User();
-        $user->name = 'user';
-        $group = new DDC2256Group();
-        $group->name = 'group';
-        $user->group = $group;
-
-        $this->em->persist($user);
-        $this->em->persist($group);
-        $this->em->flush();
-        $this->em->clear();
-
-        $sql = 'SELECT u.id, u.name, g.id as group_id, g.name as group_name FROM ddc2256_users u LEFT JOIN ddc2256_groups g ON u.group_id = g.id';
-
-        // Test ResultSetMapping.
-        $rsm = new ResultSetMapping();
-
-        $rsm->addEntityResult('MyNamespace:DDC2256User', 'u');
-        $rsm->addFieldResult('u', 'id', 'id');
-        $rsm->addFieldResult('u', 'name', 'name');
-
-        $rsm->addJoinedEntityResult('MyNamespace:DDC2256Group', 'g', 'u', 'group');
-        $rsm->addFieldResult('g', 'group_id', 'id');
-        $rsm->addFieldResult('g', 'group_name', 'name');
-
-        self::assertCount(1, $this->em->createNativeQuery($sql, $rsm)->getResult());
-
-        // Test ResultSetMappingBuilder.
-        $rsm = new ResultSetMappingBuilder($this->em);
-        $rsm->addRootEntityFromClassMetadata('MyNamespace:DDC2256User', 'u');
-        $rsm->addJoinedEntityFromClassMetadata('MyNamespace:DDC2256Group', 'g', 'u', 'group', ['id' => 'group_id', 'name' => 'group_name']);
-
-        self::assertCount(1, $this->em->createNativeQuery($sql, $rsm)->getResult());
-    }
-}
-
-/**
- * @ORM\Entity
- * @ORM\Table(name="ddc2256_users")
- */
-class DDC2256User
-{
-    /**
-     * @ORM\Id
-     * @ORM\Column(type="integer")
-     * @ORM\GeneratedValue(strategy="AUTO")
-     */
-    public $id;
-
-    /**
-     * @ORM\Column(type="string")
-     */
-    public $name;
-
-    /**
-     * @ORM\ManyToOne(targetEntity=DDC2256Group::class, inversedBy="users")A
-     * @ORM\JoinColumn(name="group_id")
-     */
-    public $group;
-}
-
-/**
- * @ORM\Entity
- * @ORM\Table(name="ddc2256_groups")
- */
-class DDC2256Group
-{
-    /**
-     * @ORM\Id
-     * @ORM\Column(type="integer")
-     * @ORM\GeneratedValue(strategy="AUTO")
-     */
-    public $id;
-
-    /**
-     * @ORM\Column(type="string")
-     */
-    public $name;
-
-    /**
-     * @ORM\OneToMany(targetEntity=DDC2256User::class, mappedBy="group")
-     */
-    public $users;
-
-    public function __construct()
-    {
-        $this->users = new \Doctrine\Common\Collections\ArrayCollection();
-    }
-}
diff --git a/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php b/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php
index 0120dfb7e23..619621e1486 100644
--- a/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php
+++ b/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php
@@ -149,29 +149,6 @@ public function testIsTransient()
         self::assertFalse($em->getMetadataFactory()->isTransient(CmsArticle::class));
     }
 
-    /**
-     * @group DDC-1512
-     */
-    public function testIsTransientEntityNamespace()
-    {
-        $cmf = new ClassMetadataFactory();
-        $driver = $this->createMock(MappingDriver::class);
-        $driver->expects($this->at(0))
-               ->method('isTransient')
-               ->with($this->equalTo(CmsUser::class))
-               ->will($this->returnValue(true));
-        $driver->expects($this->at(1))
-               ->method('isTransient')
-               ->with($this->equalTo(CmsArticle::class))
-               ->will($this->returnValue(false));
-
-        $em = $this->createEntityManager($driver);
-        $em->getConfiguration()->addEntityNamespace('CMS', 'Doctrine\Tests\Models\CMS');
-
-        self::assertTrue($em->getMetadataFactory()->isTransient('CMS:CmsUser'));
-        self::assertFalse($em->getMetadataFactory()->isTransient('CMS:CmsArticle'));
-    }
-
     public function testAddDefaultDiscriminatorMap()
     {
         $cmf = new ClassMetadataFactory();
diff --git a/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php b/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php
index 3989b57102c..db57ba995c3 100644
--- a/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php
+++ b/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php
@@ -92,13 +92,6 @@ public function testRejectsInvalidDQL($dql)
     {
         $this->expectException(QueryException::class);
 
-        $this->em->getConfiguration()->setEntityNamespaces(
-            [
-            'Unknown' => 'Unknown',
-            'CMS' => 'Doctrine\Tests\Models\CMS'
-            ]
-        );
-
         $this->parseDql($dql);
     }
 
@@ -116,19 +109,12 @@ public function invalidDQL()
 
             /* Checks for invalid AbstractSchemaName */
             ['SELECT u FROM UnknownClass u'],  // unknown
-            ['SELECT u FROM Unknown\Class u'], // unknown with namespace
             ['SELECT u FROM \Unknown\Class u'], // unknown, leading backslash
             ['SELECT u FROM Unknown\\\\Class u'], // unknown, syntactically bogus (duplicate \\)
             ['SELECT u FROM Unknown\Class\ u'], // unknown, syntactically bogus (trailing \)
-            ['SELECT u FROM Unknown:Class u'], // unknown, with namespace alias
             ['SELECT u FROM Unknown::Class u'], // unknown, with PAAMAYIM_NEKUDOTAYIM
-            ['SELECT u FROM Unknown:Class:Name u'], // unknown, with invalid namespace alias
-            ['SELECT u FROM UnknownClass: u'], // unknown, with invalid namespace alias
-            ['SELECT u FROM Unknown:Class: u'], // unknown, with invalid namespace alias
             ['SELECT u FROM Doctrine\Tests\Models\CMS\\\\CmsUser u'], // syntactically bogus (duplicate \\)array('SELECT u FROM Doctrine\Tests\Models\CMS\CmsUser\ u'), // syntactically bogus (trailing \)
             ['SELECT u FROM CMS::User u'],
-            ['SELECT u FROM CMS:User: u'],
-            ['SELECT u FROM CMS:User:Foo u'],
 
             /* Checks for invalid AliasResultVariable */
             ['SELECT \'foo\' AS \foo FROM Doctrine\Tests\Models\CMS\CmsUser u'],
diff --git a/tests/Doctrine/Tests/ORM/Query/ParserTest.php b/tests/Doctrine/Tests/ORM/Query/ParserTest.php
index cb13ee6dd71..237644a39e5 100644
--- a/tests/Doctrine/Tests/ORM/Query/ParserTest.php
+++ b/tests/Doctrine/Tests/ORM/Query/ParserTest.php
@@ -47,32 +47,6 @@ public function testAbstractSchemaNameSupportsIdentifier()
         self::assertEquals(\stdClass::class, $parser->AbstractSchemaName());
     }
 
-    /**
-     * @covers \Doctrine\ORM\Query\Parser::AbstractSchemaName
-     * @group DDC-3715
-     */
-    public function testAbstractSchemaNameSupportsNamespaceAlias()
-    {
-        $parser = $this->createParser('CMS:CmsUser');
-
-        $parser->getEntityManager()->getConfiguration()->addEntityNamespace('CMS', 'Doctrine\Tests\Models\CMS');
-
-        self::assertEquals(CmsUser::class, $parser->AbstractSchemaName());
-    }
-
-    /**
-     * @covers \Doctrine\ORM\Query\Parser::AbstractSchemaName
-     * @group DDC-3715
-     */
-    public function testAbstractSchemaNameSupportsNamespaceAliasWithRelativeClassname()
-    {
-        $parser = $this->createParser('Model:CMS\CmsUser');
-
-        $parser->getEntityManager()->getConfiguration()->addEntityNamespace('Model', 'Doctrine\Tests\Models');
-
-        self::assertEquals(CmsUser::class, $parser->AbstractSchemaName());
-    }
-
     /**
      * @dataProvider validMatches
      * @covers Doctrine\ORM\Query\Parser::match