diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index eafecb4..1e48cd6 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -159,7 +159,7 @@ jobs:
 
         pushd /tmp/test-nix-darwin-submodules
           /usr/bin/sed -i.bak \
-            '\#modules = \[#s#darwin.darwinModules.simple#./simple.nix#' \
+            '\#modules = \[#s#configuration#configuration ./simple.nix#' \
             ./flake.nix
           /usr/bin/sed -i.bak \
             's#pkgs.vim#pkgs."${import ./submodule-test/hello.nix}"#' \
@@ -241,7 +241,7 @@ jobs:
 
         pushd /tmp/test-nix-darwin-submodules
           /usr/bin/sed -i.bak \
-            '\#modules = \[#s#darwin.darwinModules.simple#./simple.nix#' \
+            '\#modules = \[#s#configuration#configuration ./simple.nix#' \
             ./flake.nix
           /usr/bin/sed -i.bak \
             's#pkgs.vim#pkgs."${import ./submodule-test/hello.nix}"#' \
diff --git a/modules/examples/flake/flake.nix b/modules/examples/flake/flake.nix
index 2c5f90e..0ada852 100644
--- a/modules/examples/flake/flake.nix
+++ b/modules/examples/flake/flake.nix
@@ -10,18 +10,33 @@
   outputs = { self, darwin, nixpkgs }:
   let
     configuration = { pkgs, ... }: {
-      nix.package = pkgs.nixVersions.stable;
+      # List packages installed in system profile. To search by name, run:
+      # $ nix-env -qaP | grep wget
+      environment.systemPackages =
+        [ pkgs.vim
+        ];
 
-      # FIXME: for github actions, this shouldn't be in the example.
+      # Auto upgrade nix package and the daemon service.
       services.nix-daemon.enable = true;
+      # nix.package = pkgs.nix;
+
+      # Necessary for using flakes on this system.
+      nix.settings.experimental-features = "nix-command flakes";
+
+      # Create /etc/zshrc that loads the nix-darwin environment.
+      programs.zsh.enable = true;  # default shell on catalina
+      # programs.fish.enable = true;
+
+      # Used for backwards compatibility, please read the changelog before changing.
+      # $ darwin-rebuild changelog
+      system.stateVersion = 4;
     };
   in
   {
     # Build darwin flake using:
-    # $ darwin-rebuild build --flake ./modules/examples#simple \
-    #       --override-input darwin .
+    # $ darwin-rebuild build --flake .#simple
     darwinConfigurations."simple" = darwin.lib.darwinSystem {
-      modules = [ configuration darwin.darwinModules.simple ];
+      modules = [ configuration ];
       system = "x86_64-darwin";
     };