diff --git a/pkgs/by-name/be/beecrypt/package.nix b/pkgs/by-name/be/beecrypt/package.nix
index f38ead8ebbf0..df752b17d569 100644
--- a/pkgs/by-name/be/beecrypt/package.nix
+++ b/pkgs/by-name/be/beecrypt/package.nix
@@ -13,6 +13,11 @@ stdenv.mkDerivation rec {
     url = "mirror://sourceforge/beecrypt/beecrypt-${version}.tar.gz";
     sha256 = "0pf5k1c4nsj77jfq5ip0ra1gzx2q47xaa0s008fnn6hd11b1yvr8";
   };
+
+  postPatch = ''
+    sed -i '33i #include "beecrypt/endianness.h"' blockmode.c
+  '';
+
   buildInputs = [ m4 ];
   configureFlags = [
     "--disable-optimized"