diff --git a/internal/tun2/connection.go b/internal/tun2/connection.go
index aa79c81..20f05dc 100644
--- a/internal/tun2/connection.go
+++ b/internal/tun2/connection.go
@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"context"
 	"io"
+	"io/ioutil"
 	"net"
 	"net/http"
 	"time"
@@ -138,12 +139,20 @@ func (c *Connection) RoundTrip(req *http.Request) (*http.Response, error) {
 	if err != nil {
 		return nil, errors.Wrap(err, ErrCantReadResponse.Error())
 	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, errors.Wrap(err, "can't read response body")
+	}
 
 	resp.Body = &mixedReadCloser{
 		Reader: buf,
 		Closer: stream,
 	}
 
+	resp.ContentLength = int64(len(body))
+
 	return resp, nil
 }