diff --git a/docs/compile/build_howto_unix.txt b/docs/compile/build_howto_unix.txt
index f6438e5..9c7ada5 100644
--- a/docs/compile/build_howto_unix.txt
+++ b/docs/compile/build_howto_unix.txt
@@ -6,6 +6,9 @@ make -C /opt/zapret2 systemd
 * linux static :
 
 need any x86_64 classic linux distribution
+tested on debian/ubuntu/fedora 2020+
+if your distro is very exotic, old or not glibc based you can debootstrap a modern debian/ubuntu system and chroot to it
+NOTE: it's not possible to build luajit in chroot under standard openwrt kernel. build process requires 32-bit x86 support, kernel is compiled without it.
 
 optionally review "common.inc" for Lua and LuaJIT versions