1 files changed, 5 insertions, 1 deletions
diff --git a/nixpkgs/pkgs/development/ocaml-modules/pipebang/default.nix b/nixpkgs/pkgs/development/ocaml-modules/pipebang/default.nix
index 489ca3d2c708..251aeb8de8ec 100644
--- a/nixpkgs/pkgs/development/ocaml-modules/pipebang/default.nix
+++ b/nixpkgs/pkgs/development/ocaml-modules/pipebang/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildOcaml, fetchFromGitHub }:
+{ lib, buildOcaml, fetchFromGitHub, camlp4 }:
 
 buildOcaml rec {
   pname = "pipebang";
@@ -13,6 +13,10 @@ buildOcaml rec {
     sha256 = "sha256-9A3X/ciL5HtuKQ5awS+hDDBLL5ytOr12wHsmJLNRn+Q=";
   };
 
+  strictDeps = true;
+
+  buildInputs = [ camlp4 ];
+
   meta = with lib; {
     homepage = "https://github.com/janestreet/pipebang";
     description = "Syntax extension to transform x |! f into f x";