diff --git a/flake.nix b/flake.nix
index 583b1a8..2458805 100644
--- a/flake.nix
+++ b/flake.nix
@@ -6,6 +6,7 @@
     flake-parts.url = "github:hercules-ci/flake-parts";
     lean = {
       url = "github:leanprover/lean4?ref=b4caee80a3dfc5c9619d88b16c40cc3db90da4e2";
+      # Do not follow input's nixpkgs since it could cause build failures
     };
     lspec = {
       url = "github:lurk-lab/LSpec?ref=3388be5a1d1390594a74ec469fd54a5d84ff6114";