diff --git a/http.go b/http.go
index 2ae86e8763..3805333ea7 100644
--- a/http.go
+++ b/http.go
@@ -771,7 +771,7 @@ func (req *Request) ResetBody() {
 func (req *Request) CopyTo(dst *Request) {
 	req.copyToSkipBody(dst)
 	if req.bodyRaw != nil {
-		dst.bodyRaw = append(dst.bodyRaw, req.bodyRaw...)
+		dst.bodyRaw = append(dst.bodyRaw[:0], req.bodyRaw...)
 		if dst.body != nil {
 			dst.body.Reset()
 		}