diff --git a/nixos/modules/programs/environment.nix b/nixos/modules/programs/environment.nix
index 4d762314298..66eb8348266 100644
--- a/nixos/modules/programs/environment.nix
+++ b/nixos/modules/programs/environment.nix
@@ -21,6 +21,7 @@ in
         PAGER = mkDefault "less -R";
         EDITOR = mkDefault "nano";
         XCURSOR_PATH = [ "$HOME/.icons" ];
+        XDG_CONFIG_DIRS = [ "/etc/xdg" ]; # needs to be before profile-relative paths to allow changes through environment.etc
       };
 
     environment.profiles = mkAfter
diff --git a/pkgs/tools/X11/xdg-user-dirs/default.nix b/pkgs/tools/X11/xdg-user-dirs/default.nix
index c72fab015d9..066b566be1f 100644
--- a/pkgs/tools/X11/xdg-user-dirs/default.nix
+++ b/pkgs/tools/X11/xdg-user-dirs/default.nix
@@ -11,8 +11,9 @@ stdenv.mkDerivation rec {
   buildInputs = [ libxslt docbook_xsl makeWrapper ];
 
   preFixup = ''
+    # fallback values need to be last
     wrapProgram "$out/bin/xdg-user-dirs-update" \
-      --prefix XDG_CONFIG_DIRS : "$out/etc/xdg"
+      --suffix XDG_CONFIG_DIRS : "$out/etc/xdg"
   '';
 
   meta = with stdenv.lib; {