diff --git a/pkgs/development/libraries/libvirt/default.nix b/pkgs/development/libraries/libvirt/default.nix
index 1d1945af319..16a4498f54c 100644
--- a/pkgs/development/libraries/libvirt/default.nix
+++ b/pkgs/development/libraries/libvirt/default.nix
@@ -6,7 +6,7 @@
 , dnsmasq, libnl, libpcap, libxslt, xhtml1, numad, numactl, perlPackages
 , curl, libiconv, gmp, xen
 }:
-
+# if you update, also bump pythonPackages.libvirt or it will break
 stdenv.mkDerivation rec {
   name = "libvirt-${version}";
   version = "1.3.3";