diff --git a/modules/nix-darwin-unmanaged.nix b/modules/nix-darwin-unmanaged.nix
index 6644a7c..462c93f 100644
--- a/modules/nix-darwin-unmanaged.nix
+++ b/modules/nix-darwin-unmanaged.nix
@@ -1,4 +1,15 @@
-{ lib, ... }: {
+{ lib, pkgs, ... }:
+let
+  failWithoutDeterminateMessage = ''
+    if ! /usr/local/bin/determinate-nixd status > /dev/null 2>&1 ; then
+      echo "Determinate is not installed."
+      echo "Download and install the Determinate package before activating the nix-darwin module."
+      echo ""
+      echo "https://docs.determinate.systems/get-started"
+      exit 1
+    fi
+  '';
+in {
   # Disable some modules that conflict with determinate-nixd.
   disabledModules = [
     # Wants to add an outdated Nix to the environment, manage nix.conf, manage the
@@ -72,4 +83,25 @@
 
   # Determinate.pkg can handle fixing build users itself.
   config.system.checks.verifyBuildUsers = false;
+
+
+  ### Help the user migrate from managed to unmanaged
+
+  # Scenario: user has an upstream Nix installation that they want to transition to Determinate
+  config.system.activationScripts.preActivation.text = lib.mkBefore failWithoutDeterminateMessage;
+  config.system.activationScripts.preUserActivation.text = lib.mkBefore failWithoutDeterminateMessage;
+
+  # Scenario: user has previously used the "default" determinate module before we went to an unmanaged nix.
+  #
+  # The symlinks defeat nix-darwin's activation-time unload/update/reload logic for launchd services.
+  # Because the symlink points to the file, they have the same content, nix-darwin won't try to update or reload the service.
+  #
+  # It also defeats nix-darwin's deletion logic, which will delete any LaunchDaemon that was managed by the previously active generation and is not present in the now-activating generation.
+  # Since the file will now exist in the new profile's LaunchDaemons directory, it will not be deleted.
+  config.environment.launchDaemons."systems.determinate.nix-store.plist".source = pkgs.runCommand "nix-store-ln" {} ''
+    ln -s /Library/LaunchDaemons/systems.determinate.nix-store.plist $out
+  '';
+  config.environment.launchDaemons."systems.determinate.nix-daemon.plist".source = pkgs.runCommand "nix-daemon-ln" {} ''
+    ln -s /Library/LaunchDaemons/systems.determinate.nix-daemon.plist $out
+  '';
 }