diff --git a/tests/integration/database/TransferOwnershipTest.php b/tests/integration/database/TransferOwnershipTest.php
new file mode 100644
index 000000000..132a79202
--- /dev/null
+++ b/tests/integration/database/TransferOwnershipTest.php
@@ -0,0 +1,144 @@
+<?php
+
+namespace OCA\Deck\Service;
+
+use OCA\Deck\Db\Acl;
+use OCA\Deck\Db\AssignedUsersMapper;
+use OCA\Deck\Db\Board;
+
+/**
+ * @group DB
+ * @coversDefaultClass OCA\Deck\Service\BoardService
+ */
+class AssignedUsersMapperTest extends \Test\TestCase {
+	private const TEST_OWNER = 'test-share-user1';
+	private const TEST_NEW_OWNER = 'target';
+	private const TEST_GROUP = 'test-share-user1';
+
+	/** @var BoardService */
+	protected $boardService;
+	/** @var CardService */
+	protected $cardService;
+	/** @var StackService */
+	protected $stackService;
+	/** @var AssignedUsersMapper */
+	protected $assignedUsersMapper;
+	/** @var AssignmentService */
+	private $assignmentService;
+    /** @var Board */
+    private $board;
+    private $cards;
+    private $stacks;
+
+    public static function setUpBeforeClass(): void {
+		parent::setUpBeforeClass();
+
+		$backend = new \Test\Util\User\Dummy();
+		\OC_User::useBackend($backend);
+		\OC::$server->getUserManager()->registerBackend($backend);
+		$backend->createUser(self::TEST_OWNER, self::TEST_OWNER);
+		$backend->createUser(self::TEST_NEW_OWNER, self::TEST_NEW_OWNER);
+		// create group
+		$groupBackend = new \Test\Util\Group\Dummy();
+		$groupBackend->createGroup(self::TEST_GROUP);
+		$groupBackend->addToGroup(self::TEST_OWNER, self::TEST_GROUP);
+		\OC::$server->getGroupManager()->addBackend($groupBackend);
+	}
+
+	public function setUp(): void {
+		parent::setUp();
+		\OC::$server->getUserSession()->login(self::TEST_OWNER, self::TEST_OWNER);
+		$this->boardService = \OC::$server->query(BoardService::class);
+		$this->stackService = \OC::$server->query(StackService::class);
+		$this->cardService = \OC::$server->query(CardService::class);
+		$this->assignmentService = \OC::$server->query(AssignmentService::class);
+		$this->assignedUsersMapper = \OC::$server->query(AssignedUsersMapper::class);
+		$this->createBoardWithExampleData();
+	}
+
+	public function createBoardWithExampleData() {
+		$stacks = [];
+		$board = $this->boardService->create('Test', self::TEST_OWNER, '000000');
+		$id = $board->getId();
+        $this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_OWNER, true, true, true);
+        $this->boardService->addAcl($id, Acl::PERMISSION_TYPE_GROUP, self::TEST_GROUP, true, true, true);
+		$stacks[] = $this->stackService->create('Stack A', $id, 1);
+		$stacks[] = $this->stackService->create('Stack B', $id, 1);
+		$stacks[] = $this->stackService->create('Stack C', $id, 1);
+		$cards[] = $this->cardService->create('Card 1', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
+		$cards[] = $this->cardService->create('Card 2', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
+        $this->assignmentService->assignUser($cards[0]->getId(), self::TEST_OWNER);
+        $this->board = $board;
+		$this->cards = $cards;
+		$this->stacks = $stacks;
+	}
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTransferBoardOwnership()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $board = $this->boardService->find($this->board->getId());
+        $boardOwner = $board->getOwner();
+        $this->assertEquals(self::TEST_NEW_OWNER, $boardOwner);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTransferACLOwnership()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $board = $this->boardService->find($this->board->getId());
+        $acl = $board->getAcl();
+        $isTargetInAcl = (bool)array_filter($acl, function ($item) {
+            return $item->getParticipant() === self::TEST_NEW_OWNER && $item->getType() === Acl::PERMISSION_TYPE_USER;
+        });
+        $this->assertTrue($isTargetInAcl);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testNoTransferAclOwnershipIfGroupType()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $board = $this->boardService->find($this->board->getId());
+        $acl = $board->getAcl();
+        $isGroupInAcl = (bool)array_filter($acl, function ($item) {
+            return $item->getParticipant() === self::TEST_GROUP && $item->getType() === Acl::PERMISSION_TYPE_GROUP;
+        });
+        $this->assertTrue($isGroupInAcl);
+    }
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTransferCardOwnership()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $card = $this->cardService->find($this->cards[0]->getId());
+        $cardOwner = $card->getOwner();
+        $this->assertEquals(self::TEST_NEW_OWNER, $cardOwner);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testReassignCardToNewOwner()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
+        $participantsUIDs = [];
+        foreach ($assignedUsers as $user) {
+            $participantsUIDs[] = $user->getParticipant();
+        }
+        $this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
+        $this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+    }
+
+	public function tearDown(): void {
+		$this->boardService->deleteForce($this->board->getId());
+		parent::tearDown();
+	}
+}