diff --git a/pkgs/by-name/bm/bmake/package.nix b/pkgs/by-name/bm/bmake/package.nix
index 3a1185122339..148beb122af7 100644
--- a/pkgs/by-name/bm/bmake/package.nix
+++ b/pkgs/by-name/bm/bmake/package.nix
@@ -96,8 +96,8 @@ stdenv.mkDerivation (finalAttrs: {
     # `boot-strap op=install` runs the built bmake, which breaks cross builds.
     install -Dm755 bmake $out/bin/bmake
     install -Dm644 bmake.1 $man/share/man/man1/bmake.1
-    mkdir -p $out/share
-    cp -r mk $out/share
+    install -Dm755 -d $out/share/mk
+    sh mk/install-mk -v -m 444 $out/share/mk
 
     runHook postInstall
   '';