diff --git a/nixos/lib/testing-python.nix b/nixos/lib/testing-python.nix
index a7f6d7926514..36394c594b2b 100644
--- a/nixos/lib/testing-python.nix
+++ b/nixos/lib/testing-python.nix
@@ -218,12 +218,12 @@ in rec {
       '';
 
       testScript = ''
-        startAll;
-        $client->waitForUnit("multi-user.target");
+        start_all()
+        client.wait_for_unit("multi-user.target")
         ${preBuild}
-        $client->succeed("env -i ${bash}/bin/bash ${buildrunner} /tmp/xchg/saved-env >&2");
+        client.succeed("env -i ${bash}/bin/bash ${buildrunner} /tmp/xchg/saved-env >&2")
         ${postBuild}
-        $client->succeed("sync"); # flush all data before pulling the plug
+        client.succeed("sync") # flush all data before pulling the plug
       '';
 
       vmRunCommand = writeText "vm-run" ''
@@ -274,7 +274,7 @@ in rec {
         machine = client;
         preBuild =
           ''
-            $client->waitForX;
+            client.wait_for_x()
           '';
       } // args);