diff --git a/component/simple-obfs/http.go b/component/simple-obfs/http.go
index ab1b59b7..11894357 100644
--- a/component/simple-obfs/http.go
+++ b/component/simple-obfs/http.go
@@ -67,7 +67,10 @@ func (ho *HTTPObfs) Write(b []byte) (int, error) {
 		req.Header.Set("User-Agent", fmt.Sprintf("curl/7.%d.%d", rand.Int()%54, rand.Int()%2))
 		req.Header.Set("Upgrade", "websocket")
 		req.Header.Set("Connection", "Upgrade")
-		req.Host = fmt.Sprintf("%s:%s", ho.host, ho.port)
+		req.Host = ho.host
+		if ho.port != "80" {
+			req.Host = fmt.Sprintf("%s:%s", ho.host, ho.port)
+		}
 		req.Header.Set("Sec-WebSocket-Key", base64.URLEncoding.EncodeToString(randBytes))
 		req.ContentLength = int64(len(b))
 		err := req.Write(ho.Conn)