diff --git a/config/home-manager/base.nix b/config/home-manager/base.nix
index 4f0f66b1..c1d2e9d8 100644
--- a/config/home-manager/base.nix
+++ b/config/home-manager/base.nix
@@ -67,7 +67,6 @@ desktop: { pkgs, ... }: {
         onNotifyPost = if desktop then "${pkgs.notmuch}/bin/notmuch new && ${pkgs.libnotify}/bin/notify-send 'New mail arrived'" else "${pkgs.notmuch}/bin/notmuch new";
       };
       mbsync = {
-        flatten = "__";
         enable = true;
         create = "both";
         expunge = "both";