diff --git a/lib/private/Files/Config/UserMountCache.php b/lib/private/Files/Config/UserMountCache.php
index a674165230..0b9501b444 100644
--- a/lib/private/Files/Config/UserMountCache.php
+++ b/lib/private/Files/Config/UserMountCache.php
@@ -135,16 +135,19 @@ class UserMountCache implements IUserMountCache {
 	 * @return ICachedMountInfo[]
 	 */
 	private function findChangedMounts(array $newMounts, array $cachedMounts) {
+		$new = [];
+		foreach ($newMounts as $mount) {
+			$new[$mount->getRootId()] = $mount;
+		}
 		$changed = [];
-		foreach ($newMounts as $newMount) {
-			foreach ($cachedMounts as $cachedMount) {
+		foreach ($cachedMounts as $cachedMount) {
+			$rootId = $cachedMount->getRootId();
+			if (isset($new[$rootId])) {
+				$newMount = $new[$rootId];
 				if (
-					$newMount->getRootId() === $cachedMount->getRootId() &&
-					(
-						$newMount->getMountPoint() !== $cachedMount->getMountPoint() ||
-						$newMount->getStorageId() !== $cachedMount->getStorageId() ||
-						$newMount->getMountId() !== $cachedMount->getMountId()
-					)
+					$newMount->getMountPoint() !== $cachedMount->getMountPoint() ||
+					$newMount->getStorageId() !== $cachedMount->getStorageId() ||
+					$newMount->getMountId() !== $cachedMount->getMountId()
 				) {
 					$changed[] = $newMount;
 				}
@@ -197,7 +200,7 @@ class UserMountCache implements IUserMountCache {
 		}
 		$mount_id = $row['mount_id'];
 		if (!is_null($mount_id)) {
-			$mount_id = (int) $mount_id;
+			$mount_id = (int)$mount_id;
 		}
 		return new CachedMountInfo($user, (int)$row['storage_id'], (int)$row['root_id'], $row['mount_point'], $mount_id, isset($row['path']) ? $row['path'] : '');
 	}