diff --git a/request.go b/request.go
index dbdf888..5a7579a 100644
--- a/request.go
+++ b/request.go
@@ -19,6 +19,10 @@ func (v *Viber) PostData(url string, i interface{}) ([]byte, error) {
 	req, err := http.NewRequest("POST", url, bytes.NewBuffer(b))
 	req.Header.Add("X-Viber-Auth-Token", v.AppKey)
 	req.Close = true
+	
+	if v.client == nil {
+		v.client = &http.Client{}
+	}
 
 	resp, err := v.client.Do(req)
 	if err != nil {