diff --git a/release.nix b/release.nix
index fdef628..1147141 100644
--- a/release.nix
+++ b/release.nix
@@ -90,6 +90,7 @@ let
     examples.simple = genExample ./modules/examples/simple.nix;
 
     tests.activation-scripts = makeTest ./tests/activation-scripts.nix;
+    tests.checks-nix-gc = makeTest ./tests/checks-nix-gc.nix;
     tests.environment-path = makeTest ./tests/environment-path.nix;
     tests.launchd-setenv = makeTest ./tests/launchd-setenv.nix;
     tests.networking-hostname = makeTest ./tests/networking-hostname.nix;
diff --git a/tests/checks-nix-gc.nix b/tests/checks-nix-gc.nix
new file mode 100644
index 0000000..fde6211
--- /dev/null
+++ b/tests/checks-nix-gc.nix
@@ -0,0 +1,19 @@
+{ config, pkgs, ... }:
+
+let
+  nix = pkgs.runCommand "nix-0.0.0" {} "mkdir -p $out";
+in
+
+{
+  nix.gc.automatic = true;
+  nix.package = nix;
+
+  test = ''
+    echo checking nix-gc validation >&2
+    grep "nix.gc.user = " ${config.out}/activate-user
+
+    echo checking nix-gc service in /Library/LaunchDaemons >&2
+    grep "<string>org.nixos.nix-gc</string>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
+    ! grep "<key>UserName</key>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
+  '';
+}
diff --git a/tests/services-nix-gc.nix b/tests/services-nix-gc.nix
index 19bb7b6..915d162 100644
--- a/tests/services-nix-gc.nix
+++ b/tests/services-nix-gc.nix
@@ -15,7 +15,11 @@ in
     grep "<string>org.nixos.nix-gc</string>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
     grep "<string>exec ${nix}/bin/nix-collect-garbage --delete-older-than 30d</string>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
     grep "<key>UserName</key>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
-    grep "<string>nixuser</string>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
+    ! grep "<string>nixuser</string>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
+
     ! grep "<key>KeepAlive</key>" ${config.out}/Library/LaunchDaemons/org.nixos.nix-gc.plist
+
+    echo checking nix-gc validation >&2
+    ! grep "nix.gc.user = " ${config.out}/activate-user
   '';
 }