diff --git a/unipay/init.py b/unipay/init.py
index fe47394..6342bc0 100644
--- a/unipay/init.py
+++ b/unipay/init.py
@@ -11,7 +11,7 @@ CONF = {
 		"appid": os.getenv("WXP_APPID", ""),
 		"cert_serial_no": os.getenv("WXP_SERIAL",""),
 		"private_key_pem": open(os.getenv("WXP_PRIVKEY","./merchant_private_key.pem"),"rb").read(),
-		"api_v3_key": os.getenv("WXP_API_V3_KEY","").encode()
+		"api_v3_key": os.getenv("WXP_API_V3_KEY","")
 	},
 	"paypal": {
 		"client_id": os.getenv("PP_ID",""),