diff --git a/nixos/tests/custom-ca.nix b/nixos/tests/custom-ca.nix
index 8e91bd3eead..73e47c3c9d0 100644
--- a/nixos/tests/custom-ca.nix
+++ b/nixos/tests/custom-ca.nix
@@ -11,6 +11,8 @@
 with import ../lib/testing-python.nix { inherit system pkgs; };
 
 let
+  inherit (pkgs) lib;
+
   makeCert = { caName, domain }: pkgs.runCommand "example-cert"
   { buildInputs = [ pkgs.gnutls ]; }
   ''