diff --git a/apps/files_external/lib/Lib/DependencyTrait.php b/apps/files_external/lib/Lib/DependencyTrait.php
index 79a9555de2c..ca48864ebab 100644
--- a/apps/files_external/lib/Lib/DependencyTrait.php
+++ b/apps/files_external/lib/Lib/DependencyTrait.php
@@ -26,7 +26,7 @@ trait DependencyTrait {
 	 *
 	 * @return MissingDependency[] Unsatisfied required dependencies
 	 */
-	public function checkRequiredDependencies() {
+	public function checkRequiredDependencies(): array {
 		return array_filter(
 			$this->checkDependencies(),
 			fn (MissingDependency $dependency) => !$dependency->isOptional()
diff --git a/apps/files_external/lib/Service/BackendService.php b/apps/files_external/lib/Service/BackendService.php
index 0b3eb7c1646..a577711668a 100644
--- a/apps/files_external/lib/Service/BackendService.php
+++ b/apps/files_external/lib/Service/BackendService.php
@@ -178,7 +178,7 @@ class BackendService {
 	 * @return Backend[]
 	 */
 	public function getAvailableBackends() {
-		return array_filter($this->getBackends(), fn (Backend $backend) => !$backend->checkRequiredDependencies());
+		return array_filter($this->getBackends(), fn (Backend $backend) => empty($backend->checkRequiredDependencies()));
 	}
 
 	/**