diff --git a/pkgs/by-name/_4/_4th/package.nix b/pkgs/by-name/_4/_4th/package.nix
index b0a291f9f761..325b497f082d 100644
--- a/pkgs/by-name/_4/_4th/package.nix
+++ b/pkgs/by-name/_4/_4th/package.nix
@@ -20,6 +20,11 @@ stdenv.mkDerivation (finalAttrs: {
 
   dontConfigure = true;
 
+  preBuild = ''
+    cp sources/include${if stdenv.hostPlatform.is64bit then "64" else "32"}/* sources/
+    make -C sources clean
+  '';
+
   makeFlags = [
     "-C sources"
     "CC:=$(CC)"