diff --git a/pkgs/tools/security/monkeysphere/default.nix b/pkgs/tools/security/monkeysphere/default.nix
index 0cf59dc555c..b1c36871fe6 100644
--- a/pkgs/tools/security/monkeysphere/default.nix
+++ b/pkgs/tools/security/monkeysphere/default.nix
@@ -31,8 +31,10 @@ stdenv.mkDerivation rec {
     DESTDIR=$(out)
   '';
 
-  # Not all checks pass yet (NixOS specific problems) and the tests "drain"
-  # entropy (apparently GnuPG still uses /dev/random).
+  # The tests "drain" entropy (GnuPG still uses /dev/random) and they don't run
+  # inside of the sandbox, because nixbld isn't allowed to login via SSH
+  # (/etc/passwd: "nixbld:x:1000:100:Nix build user:/build:/noshell",
+  # sshd: "User nixbld not allowed because shell /noshell does not exist").
   doCheck = false;
   preCheck = ''
     patchShebangs tests/