diff --git a/flake.nix b/flake.nix
index c1eb2e6..8adabfb 100644
--- a/flake.nix
+++ b/flake.nix
@@ -149,6 +149,7 @@
             cabal-install
             ghcid
             nixfmt-rfc-style
+            nil
             hpack
             hlint
           ];