diff --git a/lib/Versions/VersionsBackend.php b/lib/Versions/VersionsBackend.php
index c96280910..70976cee1 100644
--- a/lib/Versions/VersionsBackend.php
+++ b/lib/Versions/VersionsBackend.php
@@ -148,7 +148,7 @@ public function getVersionsForFile(IUser $user, FileInfo $file): array {
 	private function getVersionsForFileFromDB(FileInfo $fileInfo, IUser $user): array {
 		$folder = $this->getFolderForFile($fileInfo);
 		$mountPoint = $fileInfo->getMountPoint();
-		if (!$mountPoint instanceof GroupMountPoint) {
+		if (!$fileInfo->getStorage()->instanceOfStorage(GroupFolderStorage::class)) {
 			return [];
 		}
 		$versionsFolder = $this->getVersionFolderForFile($fileInfo);
@@ -328,9 +328,8 @@ public function deleteVersion(IVersion $version): void {
 		}
 
 		$sourceFile = $version->getSourceFile();
-		$mount = $sourceFile->getMountPoint();
 
-		if (!($mount instanceof GroupMountPoint)) {
+		if (!$sourceFile->getStorage()->instanceOfStorage(GroupFolderStorage::class)) {
 			return;
 		}
 
@@ -399,8 +398,7 @@ private function currentUserHasPermissions(FileInfo $sourceFile, int $permission
 	 * @psalm-suppress MethodSignatureMismatch - The signature of the method is correct, but psalm somehow can't understand it
 	 */
 	public function importVersionsForFile(IUser $user, Node $source, Node $target, array $versions): void {
-		$mount = $target->getMountPoint();
-		if (!($mount instanceof GroupMountPoint)) {
+		if (!$target->getStorage()->instanceOfStorage(GroupFolderStorage::class)) {
 			return;
 		}