diff --git a/overlays/show-files-to-be-deleted/default.nix b/overlays/show-files-to-be-deleted/default.nix
new file mode 100644
index 0000000..7f70a0c
--- /dev/null
+++ b/overlays/show-files-to-be-deleted/default.nix
@@ -0,0 +1,11 @@
+{ inputs, ... }:
+{
+  flake.overlays.show-files-to-be-deleted =
+    final: prev: {
+      show-files-to-be-deleted = final.writeShellScriptBin "show-files-to-be-deleted" ''
+        [ $(id -u) == 0 ] || exec sudo $0
+        find / -mount -type f
+      '';
+    };
+}
+