diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index 56615807f4e..c0b0dd8c302 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -1154,11 +1154,7 @@ private function getCommitOrder(array $entityChangeSet = null)
 
                 $joinColumns = reset($assoc['joinColumns']);
 
-                $calc->addDependency(
-                    $targetClass->name,
-                    $class->name,
-                    (int) (($joinColumns['nullable'] ?? true) === false)
-                );
+                $calc->addDependency($targetClass->name, $class->name, (int)empty($joinColumns['nullable']));
 
                 // If the target class has mapped subclasses, these share the same dependency.
                 if ( ! $targetClass->subClasses) {
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC6499Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC6499Test.php
deleted file mode 100644
index 0d86fffb037..00000000000
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC6499Test.php
+++ /dev/null
@@ -1,96 +0,0 @@
-<?php
-
-namespace Doctrine\Tests\Functional\Ticket;
-
-use Doctrine\Common\Collections\ArrayCollection;
-use Doctrine\Tests\OrmFunctionalTestCase;
-
-/**
- * @group #6499
- *
- *
- * Specifically, DDC6499B has a dependency on DDC6499A, and DDC6499A
- * has a dependency on DDC6499B. Since DDC6499A#b is not nullable,
- * the DDC6499B should be inserted first.
- */
-class DDC6499Test extends OrmFunctionalTestCase
-{
-    /**
-     * {@inheritDoc}
-     */
-    protected function setUp() : void
-    {
-        parent::setUp();
-
-        $this->_schemaTool->createSchema([
-            $this->_em->getClassMetadata(DDC6499A::class),
-            $this->_em->getClassMetadata(DDC6499B::class),
-        ]);
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    protected function tearDown() : void
-    {
-        parent::tearDown();
-
-        $this->_schemaTool->dropSchema([
-            $this->_em->getClassMetadata(DDC6499A::class),
-            $this->_em->getClassMetadata(DDC6499B::class),
-        ]);
-    }
-
-    public function testIssue() : void
-    {
-        $b = new DDC6499B();
-        $a = new DDC6499A();
-
-        $this->_em->persist($a);
-
-        $a->b = $b;
-
-        $this->_em->persist($b);
-
-        $this->_em->flush();
-
-        self::assertInternalType('integer', $a->id);
-        self::assertInternalType('integer', $b->id);
-    }
-
-    public function testIssueReversed() : void
-    {
-        $b = new DDC6499B();
-        $a = new DDC6499A();
-
-        $a->b = $b;
-
-        $this->_em->persist($b);
-        $this->_em->persist($a);
-
-        $this->_em->flush();
-
-        self::assertInternalType('integer', $a->id);
-        self::assertInternalType('integer', $b->id);
-    }
-}
-
-/** @Entity */
-class DDC6499A
-{
-    /** @Id @Column(type="integer") @GeneratedValue */
-    public $id;
-
-    /** @JoinColumn(nullable=false) @OneToOne(targetEntity=DDC6499B::class) */
-    public $b;
-}
-
-/** @Entity */
-class DDC6499B
-{
-    /** @Id @Column(type="integer") @GeneratedValue */
-    public $id;
-
-    /** @ManyToOne(targetEntity="DDC6499A") */
-    private $a;
-}