diff --git a/artiq/windows/default.nix b/artiq/windows/default.nix
index 52b3e7d..3377b10 100644
--- a/artiq/windows/default.nix
+++ b/artiq/windows/default.nix
@@ -1,3 +1,5 @@
+# This runs `run-test.nix` with `nix-build`
+
 { pkgs ? import <nixpkgs> {},
   diskImage ? "/opt/windows/c.img",
   qemuMem ? "2G",
diff --git a/artiq/windows/run-test.nix b/artiq/windows/run-test.nix
index 9b56a94..30d13d2 100644
--- a/artiq/windows/run-test.nix
+++ b/artiq/windows/run-test.nix
@@ -57,7 +57,7 @@ stdenv.mkDerivation {
       ${ssh "anaconda\\scripts\\activate ${condaEnv} && conda install artiq.tar.bz2"}
     done
 
-    # Allow tests to run for 2 minutes
+    # Schedule a timed shutdown against hanging test runs
     ${ssh "shutdown -s -t ${toString testTimeout}"}
 
     FAIL=n