diff --git a/pkgs/desktops/pantheon/desktop/elementary-gsettings-schemas/default.nix b/pkgs/desktops/pantheon/desktop/elementary-gsettings-schemas/default.nix
index dbcb992c425c..b273bbece969 100644
--- a/pkgs/desktops/pantheon/desktop/elementary-gsettings-schemas/default.nix
+++ b/pkgs/desktops/pantheon/desktop/elementary-gsettings-schemas/default.nix
@@ -44,7 +44,7 @@ runCommand "elementary-gsettings-desktop-schemas" {}
 
      cat - > $out/share/gsettings-schemas/nixos-gsettings-overrides/glib-2.0/schemas/nixos-defaults.gschema.override <<- EOF
      [org.gnome.desktop.background]
-     picture-uri='${nixos-artwork.wallpapers.simple-dark-gray}/share/artwork/gnome/nix-wallpaper-simple-dark-gray.png'
+     picture-uri='file://${nixos-artwork.wallpapers.simple-dark-gray}/share/artwork/gnome/nix-wallpaper-simple-dark-gray.png'
      primary-color='#000000'
 
      ${extraGSettingsOverrides}