diff --git a/ch6-cloud/ch6-02-lock.md b/ch6-cloud/ch6-02-lock.md
index daeb425..9d9fad2 100644
--- a/ch6-cloud/ch6-02-lock.md
+++ b/ch6-cloud/ch6-02-lock.md
@@ -176,7 +176,7 @@ func incr() {
 	// counter ++
 	getResp := client.Get(counterKey)
 	cntValue, err := getResp.Int64()
-	if err == nil {
+	if err == nil || err == redis.Nil {
 		cntValue++
 		resp := client.Set(counterKey, cntValue, 0)
 		_, err := resp.Result()