diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/GH6699Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/GH6699Test.php
new file mode 100644
index 000000000..c1e32fdef
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/GH6699Test.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\Tests\Models\CMS\CmsUser;
+use Doctrine\Tests\OrmFunctionalTestCase;
+
+/**
+ * @group 6699
+ */
+final class GH6699Test extends OrmFunctionalTestCase
+{
+    protected function setUp() : void
+    {
+        $this->useModelSet('cms');
+
+        parent::setUp();
+    }
+
+    public function testMixedParametersWithZeroNumber() : void
+    {
+        $query = $this->_em->createQueryBuilder()
+                           ->select('u')
+                           ->from(CmsUser::class, 'u')
+                           ->andWhere('u.username = :username')
+                           ->andWhere('u.id = ?0')
+                           ->getQuery();
+
+        $query->setParameter('username', 'bar');
+        $query->setParameter(0, 0);
+
+        $query->execute();
+
+        self::assertCount(2, $query->getParameters());
+        self::assertSame(0, $query->getParameter(0)->getValue());
+        self::assertSame('bar', $query->getParameter('username')->getValue());
+    }
+
+    public function testMixedParametersWithZeroNumberOnQueryBuilder() : void
+    {
+        $query = $this->_em->createQueryBuilder()
+                           ->select('u')
+                           ->from(CmsUser::class, 'u')
+                           ->andWhere('u.username = :username')
+                           ->andWhere('u.id = ?0')
+                           ->setParameter('username', 'bar')
+                           ->setParameter(0, 0)
+                           ->getQuery();
+
+        $query->execute();
+
+        self::assertCount(2, $query->getParameters());
+        self::assertSame(0, $query->getParameter(0)->getValue());
+        self::assertSame('bar', $query->getParameter('username')->getValue());
+    }
+}