diff --git a/programs/develop/kosjs/Tupfile.lua b/programs/develop/kosjs/Tupfile.lua
new file mode 100755
index 0000000000..eb80c57b14
--- /dev/null
+++ b/programs/develop/kosjs/Tupfile.lua
@@ -0,0 +1,17 @@
+if tup.getconfig("NO_GCC") ~= "" then return end
+HELPERDIR = (tup.getconfig("HELPERDIR") == "") and "../.." or tup.getconfig("HELPERDIR")
+tup.include(HELPERDIR .. "/use_gcc.lua")
+tup.include(HELPERDIR .. "/use_newlib.lua")
+
+INCLUDES = INCLUDES .. " -I ."
+
+compile_gcc{"libmujs/utftype.c", "libmujs/jsproperty.c", "libmujs/jsobject.c", "libmujs/jsdtoa.c", "libmujs/jsbuiltin.c", "libmujs/jsvalue.c", "libmujs/jsnumber.c", "libmujs/jsparse.c", "libmujs/jsstate.c", "libmujs/jsgc.c", "libmujs/jsrepr.c", "libmujs/pp.c", "libmujs/utf.c", "libmujs/jsfunction.c", "libmujs/jsdump.c", "libmujs/regexp.c", "libmujs/jsstring.c", "libmujs/jsarray.c", "libmujs/jsrun.c", "libmujs/jsdate.c", "libmujs/jscompile.c", "libmujs/jslex.c", "libmujs/jsboolean.c", "libmujs/jserror.c", "libmujs/jsintern.c", "libmujs/jsmath.c", "libmujs/jsregexp.c", "libmujs/json.c"}
+tup.rule(OBJS, "ar rcs %o %f", {"libmujs.a", "<libmujs>"})
+
+LDFLAGS = LDFLAGS .. " -Llibmujs --subsystem native"
+LIBS = LIBS .. " -lmujs"
+table.insert(LIBDEPS, "<libmujs>")
+INCLUDES = INCLUDES .. " -Ilibmujs"
+
+compile_gcc{"kosjs.c", "import.c"}
+link_gcc("kosjs")