diff --git a/c/lua/_demo/state-alloc/alloc.go b/c/lua/_demo/state-alloc/alloc.go
new file mode 100644
index 00000000..0b4ee76c
--- /dev/null
+++ b/c/lua/_demo/state-alloc/alloc.go
@@ -0,0 +1,36 @@
+package main
+
+import (
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/lua"
+)
+
+func alloc(ud c.Pointer, ptr c.Pointer, osize c.Ulong, nsize c.Ulong) c.Pointer {
+	if nsize == 0 {
+		c.Free(ptr)
+		return nil
+	} else {
+		return c.Realloc(ptr, uintptr(nsize))
+	}
+}
+
+func main() {
+	L := lua.Newstate__0(alloc, nil)
+	defer L.Close()
+	L.Openlibs()
+	if res := L.Dostring(c.Str("print('new state success')")); res != lua.OK {
+		println("newstate error")
+	}
+
+	allocf := L.Getallocf(nil)
+	L.Setallocf(allocf, nil)
+
+	if res := L.Dostring(c.Str("print('set newstate success')")); res != lua.OK {
+		println("set newstate error")
+	}
+}
+
+/* Expected output:
+new state success
+set newstate success
+*/