diff --git a/internal/backend/gs/gs.go b/internal/backend/gs/gs.go
index bc416cc32..77cbcda97 100644
--- a/internal/backend/gs/gs.go
+++ b/internal/backend/gs/gs.go
@@ -170,8 +170,7 @@ func (be *Backend) SetListMaxItems(i int) {
 // IsNotExist returns true if the error is caused by a not existing file.
 func (be *Backend) IsNotExist(err error) bool {
 	debug.Log("IsNotExist(%T, %#v)", err, err)
-	var gerr *googleapi.Error
-	return errors.As(err, &gerr) && gerr.Code == 404
+	return errors.Is(err, storage.ErrObjectNotExist)
 }
 
 // Join combines path components with slashes.