diff --git a/nixos/modules/services/audio/mpd.nix b/nixos/modules/services/audio/mpd.nix
index 9e77ee85b893..ba20b1b98d97 100644
--- a/nixos/modules/services/audio/mpd.nix
+++ b/nixos/modules/services/audio/mpd.nix
@@ -11,6 +11,10 @@ let
   cfg = config.services.mpd;
 
   mpdConf = pkgs.writeText "mpd.conf" ''
+    # This file was automatically generated by NixOS. Edit mpd's configuration
+    # via NixOS' configuration.nix, as this file will be rewritten upon mpd's
+    # restart.
+
     music_directory     "${cfg.musicDirectory}"
     playlist_directory  "${cfg.playlistDirectory}"
     ${lib.optionalString (cfg.dbFile != null) ''