diff --git a/nixos/tests/gnome-xorg.nix b/nixos/tests/gnome-xorg.nix
index 7762fff5c3a2..6ca700edcac3 100644
--- a/nixos/tests/gnome-xorg.nix
+++ b/nixos/tests/gnome-xorg.nix
@@ -5,7 +5,7 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
   };
 
   nodes.machine = { nodes, ... }: let
-    user = nodes.machine.config.users.users.alice;
+    user = nodes.machine.users.users.alice;
   in
 
     { imports = [ ./common/user-account.nix ];
@@ -43,28 +43,28 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
     };
 
   testScript = { nodes, ... }: let
-    user = nodes.machine.config.users.users.alice;
+    user = nodes.machine.users.users.alice;
     uid = toString user.uid;
     bus = "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/${uid}/bus";
     xauthority = "/run/user/${uid}/gdm/Xauthority";
     display = "DISPLAY=:0.0";
     env = "${bus} XAUTHORITY=${xauthority} ${display}";
-    gdbus = "${env} gdbus";
-    su = command: "su - ${user.name} -c '${env} ${command}'";
+    # Run a command in the appropriate user environment
+    run = command: "su - ${user.name} -c '${bus} ${command}'";
 
     # Call javascript in gnome shell, returns a tuple (success, output), where
     # `success` is true if the dbus call was successful and output is what the
     # javascript evaluates to.
-    eval = "call --session -d org.gnome.Shell -o /org/gnome/Shell -m org.gnome.Shell.Eval";
+    eval = command: run "gdbus call --session -d org.gnome.Shell -o /org/gnome/Shell -m org.gnome.Shell.Eval ${command}";
 
     # False when startup is done
-    startingUp = su "${gdbus} ${eval} Main.layoutManager._startingUp";
+    startingUp = eval "Main.layoutManager._startingUp";
 
     # Start Console
-    launchConsole = su "${bus} gapplication launch org.gnome.Console";
+    launchConsole = run "gapplication launch org.gnome.Console";
 
     # Hopefully Console's wm class
-    wmClass = su "${gdbus} ${eval} global.display.focus_window.wm_class";
+    wmClass = eval "global.display.focus_window.wm_class";
   in ''
       with subtest("Login to GNOME Xorg with GDM"):
           machine.wait_for_x()
diff --git a/nixos/tests/gnome.nix b/nixos/tests/gnome.nix
index 448a3350240c..91182790cb24 100644
--- a/nixos/tests/gnome.nix
+++ b/nixos/tests/gnome.nix
@@ -40,25 +40,25 @@ import ./make-test-python.nix ({ pkgs, lib, ...} : {
 
   testScript = { nodes, ... }: let
     # Keep line widths somewhat manageable
-    user = nodes.machine.config.users.users.alice;
+    user = nodes.machine.users.users.alice;
     uid = toString user.uid;
     bus = "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/${uid}/bus";
-    gdbus = "${bus} gdbus";
-    su = command: "su - ${user.name} -c '${command}'";
+    # Run a command in the appropriate user environment
+    run = command: "su - ${user.name} -c '${bus} ${command}'";
 
     # Call javascript in gnome shell, returns a tuple (success, output), where
     # `success` is true if the dbus call was successful and output is what the
     # javascript evaluates to.
-    eval = "call --session -d org.gnome.Shell -o /org/gnome/Shell -m org.gnome.Shell.Eval";
+    eval = command: run "gdbus call --session -d org.gnome.Shell -o /org/gnome/Shell -m org.gnome.Shell.Eval ${command}";
 
     # False when startup is done
-    startingUp = su "${gdbus} ${eval} Main.layoutManager._startingUp";
+    startingUp = eval "Main.layoutManager._startingUp";
 
     # Start Console
-    launchConsole = su "${bus} gapplication launch org.gnome.Console";
+    launchConsole = run "gapplication launch org.gnome.Console";
 
     # Hopefully Console's wm class
-    wmClass = su "${gdbus} ${eval} global.display.focus_window.wm_class";
+    wmClass = eval "global.display.focus_window.wm_class";
   in ''
       with subtest("Login to GNOME with GDM"):
           # wait for gdm to start