diff --git a/lib/private/Files/Config/UserMountCache.php b/lib/private/Files/Config/UserMountCache.php
index 66aa3a6607b9f..67b2cad7ea251 100644
--- a/lib/private/Files/Config/UserMountCache.php
+++ b/lib/private/Files/Config/UserMountCache.php
@@ -362,9 +362,9 @@ public function getMountsForFileId($fileId, $user = null) {
 			return $internalMountPath === '' || str_starts_with($internalPath, $internalMountPath . '/');
 		});
 
-		$filteredMounts = array_filter($filteredMounts, function (ICachedMountInfo $mount) {
+		$filteredMounts = array_values(array_filter($filteredMounts, function (ICachedMountInfo $mount) {
 			return $this->userManager->userExists($mount->getUser()->getUID());
-		});
+		}));
 
 		return array_map(function (ICachedMountInfo $mount) use ($internalPath) {
 			return new CachedMountFileInfo(