diff --git a/nix/kexec-installer/test.nix b/nix/kexec-installer/test.nix
index 3ff9b11..0c127eb 100644
--- a/nix/kexec-installer/test.nix
+++ b/nix/kexec-installer/test.nix
@@ -137,6 +137,7 @@ makeTest' {
     node1.succeed('/root/kexec/kexec --version >&2')
     node1.succeed('/root/kexec/run >&2')
 
+    # the kexec script will sleep 6s before doing anything, so do we here.
     time.sleep(6)
 
     # wait for kexec to finish