diff --git a/apps/updatenotification/lib/Notification/Notifier.php b/apps/updatenotification/lib/Notification/Notifier.php
index 62c4819fb1..50505ef13f 100644
--- a/apps/updatenotification/lib/Notification/Notifier.php
+++ b/apps/updatenotification/lib/Notification/Notifier.php
@@ -48,7 +48,6 @@ class Notifier implements INotifier {
 		$this->notificationManager = $notificationManager;
 		$this->l10NFactory = $l10NFactory;
 		$this->appVersions = $this->getAppVersions();
-		\OC::$server->getLogger()->error(json_encode($this->appVersions));
 	}
 
 	/**
diff --git a/apps/updatenotification/tests/Notification/NotifierTest.php b/apps/updatenotification/tests/Notification/NotifierTest.php
new file mode 100644
index 0000000000..d85cf3e707
--- /dev/null
+++ b/apps/updatenotification/tests/Notification/NotifierTest.php
@@ -0,0 +1,105 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\UpdateNotification\Tests\Notification;
+
+
+use OCA\UpdateNotification\Notification\Notifier;
+use OCP\L10N\IFactory;
+use OCP\Notification\IManager;
+use Test\TestCase;
+
+class NotifierTest extends TestCase {
+
+	/** @var IManager|\PHPUnit_Framework_MockObject_MockObject */
+	protected $notificationManager;
+	/** @var IFactory|\PHPUnit_Framework_MockObject_MockObject */
+	protected $l10nFactory;
+
+	public function setUp() {
+		parent::setUp();
+
+		$this->notificationManager = $this->getMock('OCP\Notification\IManager');
+		$this->l10nFactory = $this->getMock('OCP\L10n\IFactory');
+	}
+
+	/**
+	 * @param array $methods
+	 * @return Notifier|\PHPUnit_Framework_MockObject_MockObject
+	 */
+	protected function getNotifier(array $methods = []) {
+		if (empty($methods)) {
+			return new Notifier(
+				$this->notificationManager,
+				$this->l10nFactory
+			);
+		} {
+			return $this->getMockBuilder('OCA\UpdateNotification\Notification\Notifier')
+				->setConstructorArgs([
+					$this->notificationManager,
+					$this->l10nFactory,
+				])
+				->setMethods($methods)
+				->getMock();
+		}
+	}
+
+	public function dataUpdateAlreadyInstalledCheck() {
+		return [
+			['1.1.0', '1.0.0', false],
+			['1.1.0', '1.1.0', true],
+			['1.1.0', '1.2.0', true],
+		];
+	}
+
+	/**
+	 * @dataProvider dataUpdateAlreadyInstalledCheck
+	 *
+	 * @param string $versionNotification
+	 * @param string $versionInstalled
+	 * @param bool $exception
+	 */
+	public function testUpdateAlreadyInstalledCheck($versionNotification, $versionInstalled, $exception) {
+		$notifier = $this->getNotifier();
+
+		$notification = $this->getMock('OCP\Notification\INotification');
+		$notification->expects($this->once())
+			->method('getObjectId')
+			->willReturn($versionNotification);
+
+		if ($exception) {
+			$this->notificationManager->expects($this->once())
+				->method('markProcessed')
+				->with($notification);
+		} else {
+			$this->notificationManager->expects($this->never())
+				->method('markProcessed');
+		}
+
+		try {
+			$this->invokePrivate($notifier, 'updateAlreadyInstalledCheck', [$notification, $versionInstalled]);
+			$this->assertFalse($exception);
+		} catch (\Exception $e) {
+			$this->assertTrue($exception);
+			$this->assertInstanceOf('InvalidArgumentException', $e);
+		}
+	}
+}