diff --git a/images/nix/fake_nixpkgs/default.nix b/images/nix/fake_nixpkgs/default.nix
index e45432a..55e2369 100644
--- a/images/nix/fake_nixpkgs/default.nix
+++ b/images/nix/fake_nixpkgs/default.nix
@@ -2,6 +2,9 @@ _:
 throw ''
 This container doesn't include nixpkgs.
 
-Pin your dependencies. Or if you must, override the NIX_PATH environment
-variable with eg: "NIX_PATH=nixpkgs=channel:nixos-unstable"
+The best way to work around that is to pin your dependencies. See
+  https://nix.dev/tutorials/towards-reproducibility-pinning-nixpkgs.html
+
+Or if you must, override the NIX_PATH environment variable with eg:
+  "NIX_PATH=nixpkgs=channel:nixos-unstable"
 ''