diff --git a/src/App.php b/src/App.php
index 1fb79decea..cfe254581a 100644
--- a/src/App.php
+++ b/src/App.php
@@ -8,6 +8,7 @@ use Detection\MobileDetect;
 use DOMDocument;
 use DOMXPath;
 use Exception;
+use Friendica\Core\Logger;
 use Friendica\Database\DBA;
 use Friendica\Network\HTTPException\InternalServerErrorException;
 use Psr\Log\LoggerInterface;
diff --git a/src/Core/Logger.php b/src/Core/Logger.php
index 6102baa5a5..fe39d3feb2 100644
--- a/src/Core/Logger.php
+++ b/src/Core/Logger.php
@@ -89,7 +89,10 @@ class Logger extends BaseObject
 			return;
 		}
 
-		LoggerFactory::addStreamHandler($logger, $logfile, $loglevel);
+		$level = self::mapPSR3Level($loglevel);
+		LoggerFactory::addStreamHandler($logger, $logfile, $level);
+
+		self::$logger = $logger;
 
 		$logfile = Config::get('system', 'dlogfile');
 
@@ -185,6 +188,7 @@ class Logger extends BaseObject
 	public static function error($message, $context = [])
 	{
 		if (!isset(self::$logger)) {
+			echo "not set!?\n";
 			return;
 		}
 
diff --git a/src/Util/LoggerFactory.php b/src/Util/LoggerFactory.php
index d99093efe4..e94cd2e971 100644
--- a/src/Util/LoggerFactory.php
+++ b/src/Util/LoggerFactory.php
@@ -68,7 +68,7 @@ class LoggerFactory
 	public static function addStreamHandler($logger, $stream, $level = LogLevel::NOTICE)
 	{
 		if ($logger instanceof Monolog\Logger) {
-			$fileHandler = new Monolog\Handler\StreamHandler($stream . ".1", Monolog\Logger::toMonologLevel($level));
+			$fileHandler = new Monolog\Handler\StreamHandler($stream, Monolog\Logger::toMonologLevel($level));
 
 			$formatter = new Monolog\Formatter\LineFormatter("%datetime% %channel% [%level_name%]: %message% %context% %extra%\n");
 			$fileHandler->setFormatter($formatter);
@@ -78,4 +78,32 @@ class LoggerFactory
 			throw new InternalServerErrorException('Logger instance incompatible for MonologFactory');
 		}
 	}
+
+	/**
+	 * This method enables the test mode of a given logger
+	 *
+	 * @param LoggerInterface $logger The logger
+	 *
+	 * @return Monolog\Handler\TestHandler the Handling for tests
+	 *
+	 * @throws InternalServerErrorException if the logger is incompatible to the logger factory
+	 */
+	public static function enableTest($logger)
+	{
+		if ($logger instanceof Monolog\Logger) {
+			// disable every handler so far
+			$logger->pushHandler(new Monolog\Handler\NullHandler());
+
+			// enable the test handler
+			$fileHandler = new Monolog\Handler\TestHandler();
+			$formatter = new Monolog\Formatter\LineFormatter("%datetime% %channel% [%level_name%]: %message% %context% %extra%\n");
+			$fileHandler->setFormatter($formatter);
+
+			$logger->pushHandler($fileHandler);
+
+			return $fileHandler;
+		} else {
+			throw new InternalServerErrorException('Logger instance incompatible for MonologFactory');
+		}
+	}
 }
diff --git a/tests/include/ApiTest.php b/tests/include/ApiTest.php
index ede84a0eb9..cf7571073a 100644
--- a/tests/include/ApiTest.php
+++ b/tests/include/ApiTest.php
@@ -11,6 +11,8 @@ use Friendica\Core\PConfig;
 use Friendica\Core\Protocol;
 use Friendica\Core\System;
 use Friendica\Network\HTTPException;
+use Friendica\Util\LoggerFactory;
+use Monolog\Handler\TestHandler;
 
 require_once __DIR__ . '/../../include/api.php';
 
@@ -22,6 +24,11 @@ require_once __DIR__ . '/../../include/api.php';
  */
 class ApiTest extends DatabaseTest
 {
+	/**
+	 * @var TestHandler Can handle log-outputs
+	 */
+	protected $logOutput;
+
 	/**
 	 * Create variables used by tests.
 	 */
@@ -30,6 +37,7 @@ class ApiTest extends DatabaseTest
 		parent::setUp();
 
 		$this->app = BaseObject::getApp();
+		$this->logOutput = LoggerFactory::enableTest($this->app->getLogger());
 
 		// User data that the test database is populated with
 		$this->selfUser = [
diff --git a/tests/src/BaseObjectTest.php b/tests/src/BaseObjectTest.php
index 9743ca887f..7b9ff3aa15 100644
--- a/tests/src/BaseObjectTest.php
+++ b/tests/src/BaseObjectTest.php
@@ -41,6 +41,7 @@ class BaseObjectTest extends TestCase
 	{
 		$logger = $logger = LoggerFactory::create('test');
 		$app = new App(__DIR__ . '/../../', $logger);
+		LoggerFactory::enableTest($logger);
 		$this->assertNull($this->baseObject->setApp($app));
 		$this->assertEquals($app, $this->baseObject->getApp());
 	}