diff --git a/src/storage-rbox/libstorage-rbox-plugin.c b/src/storage-rbox/libstorage-rbox-plugin.c
index c0d9b95a..5c6ac357 100644
--- a/src/storage-rbox/libstorage-rbox-plugin.c
+++ b/src/storage-rbox/libstorage-rbox-plugin.c
@@ -20,9 +20,9 @@ static int refcount = 0;
 
 struct mail_storage rbox_storage = {
     .name = "rbox",
-    .class_flags = MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT | MAIL_STORAGE_CLASS_FLAG_FILE_PER_MSG |
-                   MAIL_STORAGE_CLASS_FLAG_HAVE_MAIL_GUIDS | MAIL_STORAGE_CLASS_FLAG_HAVE_MAIL_GUID128 |
-                   MAIL_STORAGE_CLASS_FLAG_HAVE_MAIL_SAVE_GUIDS | MAIL_STORAGE_CLASS_FLAG_BINARY_DATA,
+    .class_flags = MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT | MAIL_STORAGE_CLASS_FLAG_HAVE_MAIL_GUIDS |
+                   MAIL_STORAGE_CLASS_FLAG_HAVE_MAIL_GUID128 | MAIL_STORAGE_CLASS_FLAG_HAVE_MAIL_SAVE_GUIDS |
+                   MAIL_STORAGE_CLASS_FLAG_BINARY_DATA,
 
     .v = {
         NULL, rbox_storage_alloc, rbox_storage_create, rbox_storage_destroy, NULL, rbox_storage_get_list_settings,