Index: Makefile.inc1
===================================================================
--- Makefile.inc1
+++ Makefile.inc1
@@ -2112,8 +2112,8 @@
 # 13.0-CURRENT cycle, thus needs to be built on -older releases and stable
 # branches.
 .if ${BOOTSTRAPPING} < 1300059
-${_bt}-libexec/flua: ${_bt}-lib/liblua
-_flua= lib/liblua libexec/flua
+${_bt}-libexec/flua: ${_bt}-lib/liblua ${_bt}-lib/libucl
+_flua= lib/liblua lib/libucl libexec/flua
 .endif
 
 # r245440 mtree -N support added
Index: libexec/flua/Makefile
===================================================================
--- libexec/flua/Makefile
+++ libexec/flua/Makefile
@@ -32,4 +32,10 @@
 LIBADD+=	edit
 .endif
 
+UCLSRC?=	${SRCTOP}/contrib/libucl
+.PATH: ${UCLSRC}/lua
+SRCS+=	lua_ucl.c
+CFLAGS+=	-I${UCLSRC}/include -I${UCLSRC}/src -I${UCLSRC}/uthash
+LIBADD+=	ucl
+
 .include <bsd.prog.mk>
Index: libexec/flua/linit_flua.c
===================================================================
--- libexec/flua/linit_flua.c
+++ libexec/flua/linit_flua.c
@@ -36,6 +36,7 @@
 #include "lauxlib.h"
 #include "lfs.h"
 #include "lposix.h"
+#include "lua_ucl.h"
 
 /*
 ** these libs are loaded by lua.c and are readily available to any Lua
@@ -59,6 +60,7 @@
   {"lfs", luaopen_lfs},
   {"posix.sys.stat", luaopen_posix_sys_stat},
   {"posix.unistd", luaopen_posix_unistd},
+  {"ucl", luaopen_ucl},
   {NULL, NULL}
 };
 
Index: tools/build/Makefile
===================================================================
--- tools/build/Makefile
+++ tools/build/Makefile
@@ -149,6 +149,7 @@
 	lib/casper \
 	lib/geom \
 	usr/include/casper \
+	usr/include/private/ucl \
 	usr/include/private/zstd \
 	usr/lib \
 	usr/libexec