diff --git a/flake.nix b/flake.nix
index 2322e97..61b751e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -48,6 +48,7 @@
           src = pkgs.lib.fileset.toSource {
             root = ./.;
             fileset = pkgs.lib.fileset.unions [
+              ./.cargo
               ./Cargo.toml
               ./Cargo.lock
               ./tree-sitter-grammar-repository