diff --git a/client.go b/client.go
index 1f12d4ace..5cae78dd7 100644
--- a/client.go
+++ b/client.go
@@ -2,6 +2,7 @@ package fasthttp
 
 import (
 	"bufio"
+	"bytes"
 	"crypto/tls"
 	"errors"
 	"fmt"
@@ -477,6 +478,10 @@ func (c *Client) Do(req *Request, resp *Response) error {
 
 	host := uri.Host()
 
+	if bytes.ContainsRune(host, ',') {
+		return fmt.Errorf("invalid host %q. Use HostClient for multiple hosts", host)
+	}
+
 	isTLS := false
 	if uri.isHTTPS() {
 		isTLS = true