diff --git a/lib/private/AppFramework/App.php b/lib/private/AppFramework/App.php
index e15e4a797e..5a7bc8fad4 100644
--- a/lib/private/AppFramework/App.php
+++ b/lib/private/AppFramework/App.php
@@ -61,11 +61,12 @@ class App {
 
 		$appInfo = \OC_App::getAppInfo($appId);
 		if (isset($appInfo['namespace'])) {
-			return $topNamespace . trim($appInfo['namespace']);
+			self::$nameSpaceCache[$appId] = trim($appInfo['namespace']);
+		} else {
+			// if the tag is not found, fall back to uppercasing the first letter
+			self::$nameSpaceCache[$appId] = ucfirst($appId);
 		}
 
-		// if the tag is not found, fall back to uppercasing the first letter
-		self::$nameSpaceCache[$appId] = ucfirst($appId);
 		return $topNamespace . self::$nameSpaceCache[$appId];
 	}
 
diff --git a/lib/private/AppFramework/DependencyInjection/DIContainer.php b/lib/private/AppFramework/DependencyInjection/DIContainer.php
index 06825d2dd5..4fb13b09ae 100644
--- a/lib/private/AppFramework/DependencyInjection/DIContainer.php
+++ b/lib/private/AppFramework/DependencyInjection/DIContainer.php
@@ -49,6 +49,7 @@ use OC\ServerContainer;
 use OCP\AppFramework\Http\IOutput;
 use OCP\AppFramework\IApi;
 use OCP\AppFramework\IAppContainer;
+use OCP\AppFramework\QueryException;
 use OCP\Files\Folder;
 use OCP\Files\IAppData;
 use OCP\IL10N;
@@ -373,24 +374,40 @@ class DIContainer extends SimpleContainer implements IAppContainer {
 		});
 	}
 
+	/**
+	 * @param string $name
+	 * @return mixed
+	 * @throws QueryException if the query could not be resolved
+	 */
 	public function query($name) {
+		try {
+			return $this->queryNoFallback($name);
+		} catch (QueryException $e) {
+			return $this->getServer()->query($name);
+		}
+	}
+
+	/**
+	 * @param string $name
+	 * @return mixed
+	 * @throws QueryException if the query could not be resolved
+	 */
+	public function queryNoFallback($name) {
 		$name = $this->sanitizeName($name);
 
 		if ($this->offsetExists($name)) {
 			return parent::query($name);
 		} else {
-			if (strpos($name, 'OCA\\') === 0 && substr_count($name, '\\') >= 2) {
-				$segments = explode('\\', $name);
-				if (strtolower($segments[1]) === strtolower($this['AppName'])) {
-					return parent::query($name);
-				}
-			} else if ($this['AppName'] === 'settings' && strpos($name, 'OC\\Settings\\') === 0) {
+			if ($this['AppName'] === 'settings' && strpos($name, 'OC\\Settings\\') === 0) {
 				return parent::query($name);
 			} else if ($this['AppName'] === 'core' && strpos($name, 'OC\\Core\\') === 0) {
 				return parent::query($name);
+			} else if (strpos($name, \OC\AppFramework\App::buildAppNamespace($this['AppName']) . '\\') === 0) {
+				return parent::query($name);
 			}
 		}
 
-		return $this->getServer()->query($name);
+		throw new QueryException('Could not resolve ' . $name . '!' .
+			' Class can not be instantiated');
 	}
 }
diff --git a/lib/private/ServerContainer.php b/lib/private/ServerContainer.php
index df0293addf..e7b1ed2dad 100644
--- a/lib/private/ServerContainer.php
+++ b/lib/private/ServerContainer.php
@@ -37,12 +37,26 @@ class ServerContainer extends SimpleContainer {
 	/** @var DIContainer[] */
 	protected $appContainers;
 
+	/** @var string[] */
+	protected $namespaces;
+
 	/**
 	 * ServerContainer constructor.
 	 */
 	public function __construct() {
 		parent::__construct();
 		$this->appContainers = [];
+		$this->namespaces = [];
+	}
+
+	/**
+	 * @param string $appName
+	 * @param string $appNamespace
+	 */
+	public function registerNamespace($appName, $appNamespace) {
+		// Cut of OCA\ and lowercase
+		$appNamespace = strtolower(substr($appNamespace, strrpos($appNamespace, '\\') + 1));
+		$this->namespaces[$appNamespace] = $appName;
 	}
 
 	/**
@@ -54,15 +68,19 @@ class ServerContainer extends SimpleContainer {
 	}
 
 	/**
-	 * @param string $appName
+	 * @param string $namespace
 	 * @return DIContainer
+	 * @throws QueryException
 	 */
-	public function getAppContainer($appName) {
-		if (isset($this->appContainers[$appName])) {
-			return $this->appContainers[$appName];
+	protected function getAppContainer($namespace) {
+		if (isset($this->appContainers[$namespace])) {
+			return $this->appContainers[$namespace];
 		}
 
-		return new DIContainer($appName);
+		if (isset($this->namespaces[$namespace])) {
+			return new DIContainer($this->namespaces[$namespace]);
+		}
+		throw new QueryException();
 	}
 
 	/**
@@ -77,11 +95,11 @@ class ServerContainer extends SimpleContainer {
 		// the apps container first.
 		if (strpos($name, 'OCA\\') === 0 && substr_count($name, '\\') >= 2) {
 			$segments = explode('\\', $name);
-			$appContainer = $this->getAppContainer(strtolower($segments[1]));
 			try {
-				return $appContainer->query($name);
+				$appContainer = $this->getAppContainer(strtolower($segments[1]));
+				return $appContainer->queryNoFallback($name);
 			} catch (QueryException $e) {
-				// Didn't find the service in the respective app container,
+				// Didn't find the service or the respective app container,
 				// ignore it and fall back to the core container.
 			}
 		}
diff --git a/lib/private/legacy/app.php b/lib/private/legacy/app.php
index c82d620882..5343e7ad17 100644
--- a/lib/private/legacy/app.php
+++ b/lib/private/legacy/app.php
@@ -189,6 +189,7 @@ class OC_App {
 		self::$alreadyRegistered[$key] = true;
 		// Register on PSR-4 composer autoloader
 		$appNamespace = \OC\AppFramework\App::buildAppNamespace($app);
+		\OC::$server->registerNamespace($app, $appNamespace);
 		\OC::$composerAutoloader->addPsr4($appNamespace . '\\', $path . '/lib/', true);
 		if (defined('PHPUNIT_RUN') || defined('CLI_TEST_RUN')) {
 			\OC::$composerAutoloader->addPsr4($appNamespace . '\\Tests\\', $path . '/tests/', true);
diff --git a/lib/public/IContainer.php b/lib/public/IContainer.php
index 9dc7f9f941..f7ca069767 100644
--- a/lib/public/IContainer.php
+++ b/lib/public/IContainer.php
@@ -62,6 +62,7 @@ interface IContainer {
 	 *
 	 * @param string $name
 	 * @return mixed
+	 * @throws QueryException if the query could not be resolved
 	 * @since 6.0.0
 	 */
 	public function query($name);
diff --git a/tests/lib/Authentication/TwoFactorAuth/ManagerTest.php b/tests/lib/Authentication/TwoFactorAuth/ManagerTest.php
index 1ea17f5d30..c031c39b5f 100644
--- a/tests/lib/Authentication/TwoFactorAuth/ManagerTest.php
+++ b/tests/lib/Authentication/TwoFactorAuth/ManagerTest.php
@@ -68,7 +68,7 @@ class ManagerTest extends TestCase {
 		parent::setUp();
 
 		$this->user = $this->createMock(IUser::class);
-		$this->appManager = $this->createMock('\OC\App\AppManager');
+		$this->appManager = $this->createMock(AppManager::class);
 		$this->session = $this->createMock(ISession::class);
 		$this->config = $this->createMock(IConfig::class);
 		$this->activityManager = $this->createMock(IManager::class);
diff --git a/tests/lib/InfoXmlTest.php b/tests/lib/InfoXmlTest.php
index 4e75ca7820..18391a20c0 100644
--- a/tests/lib/InfoXmlTest.php
+++ b/tests/lib/InfoXmlTest.php
@@ -63,6 +63,14 @@ class InfoXmlTest extends TestCase {
 		$appPath = \OC_App::getAppPath($app);
 		\OC_App::registerAutoloading($app, $appPath);
 
+		//Add the appcontainer
+		$applicationClassName = \OCP\AppFramework\App::buildAppNamespace($app) . '\\AppInfo\\Application';
+		if (class_exists($applicationClassName)) {
+			$application = new $applicationClassName();
+		} else {
+			$application = new \OCP\AppFramework\App($app);
+		}
+
 		if (isset($appInfo['background-jobs'])) {
 			foreach ($appInfo['background-jobs'] as $job) {
 				$this->assertTrue(class_exists($job), 'Asserting background job "' . $job . '" exists');