diff --git a/api/anticaptcha/cli.go b/api/anticaptcha/cli.go
index cb46a8f..74e2138 100644
--- a/api/anticaptcha/cli.go
+++ b/api/anticaptcha/cli.go
@@ -17,7 +17,7 @@ type Cli struct {
 type Req struct {
 	Site string `json:"site"`
 	Data string `json:"data"`
-	Img  string `json:"img"`
+	Img  []byte `json:"img"`
 	To   int    `json:"to"`
 }
 
@@ -26,7 +26,7 @@ func (c *Cli) Recaptchav2(site string, data string) (string, error) {
 	req := &Req{
 		Site: site,
 		Data: data,
-		Img:  "",
+		Img:  nil,
 		To:   300,
 	}
 	err := c.HttpCli().JsonPost("/ipc/anticaptcha/recaptchav2", req, &ret)