diff --git a/build-depends.nix b/build-depends.nix
index 4025e7e..86c5b44 100644
--- a/build-depends.nix
+++ b/build-depends.nix
@@ -20,6 +20,7 @@ with pkgs; [
   haskellPackages.alex
   haskellPackages.BNFC
   haskellPackages.c2hs
+  haskellPackages.cpphs
   haskellPackages.happy
   haskellPackages.hspec-discover
   haskellPackages.markdown-unlit