diff --git a/doh-server/server.go b/doh-server/server.go
index d1c8793..0827c16 100644
--- a/doh-server/server.go
+++ b/doh-server/server.go
@@ -81,7 +81,6 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=UTF-8")
 	w.Header().Set("Server", "DNS-over-HTTPS/1.0 (+https://github.com/m13253/dns-over-https)")
 	w.Header().Set("X-Powered-By", "DNS-over-HTTPS/1.0 (+https://github.com/m13253/dns-over-https)")
-	w.Header().Set("Vary", "X-Edns-Client-Subnet")
 
 	name := r.FormValue("name")
 	if name == "" {
@@ -205,9 +204,6 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Cache-Control", "max-age=" + strconv.Itoa(int(respJson.LeastTTL)))
 		w.Header().Set("Expires", respJson.EarliestExpires.Format(time.RFC1123))
 	}
-	if respJson.EdnsClientSubnet != "" {
-		w.Header().Set("X-Edns-Client-Subnet", respJson.EdnsClientSubnet)
-	}
 	w.Write(respStr)
 }
 
diff --git a/json-dns/marshal.go b/json-dns/marshal.go
index d5403f1..2a0d996 100644
--- a/json-dns/marshal.go
+++ b/json-dns/marshal.go
@@ -84,8 +84,7 @@ func Marshal(msg *dns.Msg) *Response {
 					} else if ipv4 := clientAddress.To4(); ipv4 != nil {
 						clientAddress = ipv4
 					}
-					scopeMask := net.CIDRMask(int(edns0.SourceScope), len(clientAddress) * 8)
-					resp.EdnsClientSubnet = clientAddress.Mask(scopeMask).String() + "/" + strconv.Itoa(int(edns0.SourceScope))
+					resp.EdnsClientSubnet = clientAddress.String() + "/" + strconv.Itoa(int(edns0.SourceScope))
 				}
 			}
 			continue