diff --git a/pkgs/development/ocaml-modules/biniou/default.nix b/pkgs/development/ocaml-modules/biniou/default.nix
index 7047edf24b3e..97c4750002e6 100644
--- a/pkgs/development/ocaml-modules/biniou/default.nix
+++ b/pkgs/development/ocaml-modules/biniou/default.nix
@@ -1,26 +1,30 @@
 { stdenv, fetchFromGitHub, ocaml, findlib, jbuilder, easy-format }:
 
 stdenv.mkDerivation rec {
-	version = "1.2.0";
-	name = "ocaml${ocaml.version}-biniou-${version}";
-	src = fetchFromGitHub {
-		owner = "mjambon";
-		repo = "biniou";
-		rev = "v${version}";
-		sha256 = "0mjpgwyfq2b2izjw0flmlpvdjgqpq8shs89hxj1np2r50csr8dcb";
-	};
+  version = "1.2.0";
+  name = "ocaml${ocaml.version}-biniou-${version}";
+  src = fetchFromGitHub {
+    owner = "mjambon";
+    repo = "biniou";
+    rev = "v${version}";
+    sha256 = "0mjpgwyfq2b2izjw0flmlpvdjgqpq8shs89hxj1np2r50csr8dcb";
+  };
 
-	buildInputs = [ ocaml findlib jbuilder ];
+  buildInputs = [ ocaml findlib jbuilder ];
 
-	propagatedBuildInputs = [ easy-format ];
+  propagatedBuildInputs = [ easy-format ];
 
-	inherit (jbuilder) installPhase;
+  postPatch = ''
+   patchShebangs .
+  '';
 
-	meta = {
-		inherit (src.meta) homepage;
-		inherit (ocaml.meta) platforms;
-		description = "Binary data format designed for speed, safety, ease of use and backward compatibility as protocols evolve";
-		maintainers = [ stdenv.lib.maintainers.vbgl ];
-		license = stdenv.lib.licenses.bsd3;
-	};
+  inherit (jbuilder) installPhase;
+
+  meta = {
+    inherit (src.meta) homepage;
+    inherit (ocaml.meta) platforms;
+    description = "Binary data format designed for speed, safety, ease of use and backward compatibility as protocols evolve";
+    maintainers = [ stdenv.lib.maintainers.vbgl ];
+    license = stdenv.lib.licenses.bsd3;
+  };
 }