diff --git a/lib/CommandApplication.php b/lib/CommandApplication.php
index e79e6fd5..e1ad2de4 100644
--- a/lib/CommandApplication.php
+++ b/lib/CommandApplication.php
@@ -47,7 +47,7 @@ protected function getCommandName(InputInterface $input) {
 	/**
 	 * Gets the default commands that should always be available.
 	 *
-	 * @return array An array of default Command instances
+	 * @return \Symfony\Component\Console\Command\Command[] An array of default Command instances
 	 */
 	protected function getDefaultCommands() {
 		// Keep the core default commands to have the HelpCommand
diff --git a/lib/Updater.php b/lib/Updater.php
index cee81889..ddec987c 100644
--- a/lib/Updater.php
+++ b/lib/Updater.php
@@ -121,11 +121,9 @@ public function getCurrentVersion() {
 
 	/**
 	 * Returns currently used release channel
-	 *
-	 * @return string
 	 */
-	private function getCurrentReleaseChannel() {
-		return !is_null($this->getConfigOption('updater.release.channel')) ? $this->getConfigOption('updater.release.channel') : 'stable';
+	private function getCurrentReleaseChannel(): string {
+		return (string)($this->getConfigOption('updater.release.channel') ?? 'stable');
 	}
 
 	/**
@@ -176,10 +174,9 @@ public function updateAvailable() {
 	/**
 	 * Returns the specified config options
 	 *
-	 * @param string $key
 	 * @return mixed|null Null if the entry is not found
 	 */
-	public function getConfigOption($key) {
+	public function getConfigOption(string $key) {
 		return isset($this->configValues[$key]) ? $this->configValues[$key] : null;
 	}
 
@@ -1048,7 +1045,7 @@ public function endStep($step) {
 	}
 
 	/**
-	 * @return string
+	 * @return array
 	 * @throws \Exception
 	 */
 	public function currentStep() {