Problem with file operation on windows

[xpunch]

package main

import (
	"io/ioutil"
	"os"

	"github.com/gofrs/flock"
)

func main() {
	file := "test.txt"
	lock := flock.New(file)
	if err := lock.Lock(); err != nil {
		panic(err)
	}
	defer lock.Unlock()

	f, err := os.Open(file)
	if err != nil {
		panic(err)
	}
	_, err = ioutil.ReadAll(f)
	if err != nil {
		panic(err)
	}
}

panic: read test.txt: The process cannot access the file because another process has locked a portion of the file.

goroutine 1 [running]:
main.main()
        C:/github/fslock/main.go:24 +0x16b
exit status 2

[xpunch]

Should use RLock