diff --git a/nixos/tests/systemd-initrd-modprobe.nix b/nixos/tests/systemd-initrd-modprobe.nix
index bf635a10d0e9..0f93492176b4 100644
--- a/nixos/tests/systemd-initrd-modprobe.nix
+++ b/nixos/tests/systemd-initrd-modprobe.nix
@@ -2,6 +2,7 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
   name = "systemd-initrd-modprobe";
 
   nodes.machine = { pkgs, ... }: {
+    testing.initrdBackdoor = true;
     boot.initrd.systemd.enable = true;
     boot.initrd.kernelModules = [ "loop" ]; # Load module in initrd.
     boot.extraModprobeConfig = ''
@@ -10,6 +11,12 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
   };
 
   testScript = ''
+    machine.wait_for_unit("initrd.target")
+    max_loop = machine.succeed("cat /sys/module/loop/parameters/max_loop")
+    assert int(max_loop) == 42, "Parameter should be respected for initrd kernel modules"
+
+    # Make sure it sticks in stage 2
+    machine.switch_root()
     machine.wait_for_unit("multi-user.target")
     max_loop = machine.succeed("cat /sys/module/loop/parameters/max_loop")
     assert int(max_loop) == 42, "Parameter should be respected for initrd kernel modules"