diff --git a/doh-server/server.go b/doh-server/server.go
index 0827c16..f9d76db 100644
--- a/doh-server/server.go
+++ b/doh-server/server.go
@@ -84,13 +84,13 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 
 	name := r.FormValue("name")
 	if name == "" {
-		http.Error(w, jsonDNS.FormatError("Invalid argument value: \"name\""), 400)
+		jsonDNS.FormatError(w, "Invalid argument value: \"name\"", 400)
 		return
 	}
 	if punycode, err := idna.ToASCII(name); err == nil {
 		name = punycode
 	} else {
-		http.Error(w, jsonDNS.FormatError(fmt.Sprintf("Invalid argument value: \"name\" = %q (%s)", name, err.Error())), 400)
+		jsonDNS.FormatError(w, fmt.Sprintf("Invalid argument value: \"name\" = %q (%s)", name, err.Error()), 400)
 		return
 	}
 
@@ -102,7 +102,7 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 	} else if v, ok := dns.StringToType[strings.ToUpper(rrTypeStr)]; ok {
 		rrType = v
 	} else {
-		http.Error(w, jsonDNS.FormatError(fmt.Sprintf("Invalid argument value: \"type\" = %q", rrTypeStr)), 400)
+		jsonDNS.FormatError(w, fmt.Sprintf("Invalid argument value: \"type\" = %q", rrTypeStr), 400)
 		return
 	}
 
@@ -112,7 +112,7 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 		cd = true
 	} else if cdStr == "0" || cdStr == "false" || cdStr == "" {
 	} else {
-		http.Error(w, jsonDNS.FormatError(fmt.Sprintf("Invalid argument value: \"cd\" = %q", cdStr)), 400)
+		jsonDNS.FormatError(w, fmt.Sprintf("Invalid argument value: \"cd\" = %q", cdStr), 400)
 		return
 	}
 
@@ -125,7 +125,7 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 		if slash < 0 {
 			ednsClientAddress = net.ParseIP(ednsClientSubnet)
 			if ednsClientAddress == nil {
-				http.Error(w, jsonDNS.FormatError(fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet)), 400)
+				jsonDNS.FormatError(w, fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet), 400)
 				return
 			}
 			if ipv4 := ednsClientAddress.To4(); ipv4 != nil {
@@ -139,7 +139,7 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 		} else {
 			ednsClientAddress = net.ParseIP(ednsClientSubnet[:slash])
 			if ednsClientAddress == nil {
-				http.Error(w, jsonDNS.FormatError(fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet)), 400)
+				jsonDNS.FormatError(w, fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet), 400)
 				return
 			}
 			if ipv4 := ednsClientAddress.To4(); ipv4 != nil {
@@ -150,7 +150,7 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 			}
 			netmask, err := strconv.ParseUint(ednsClientSubnet[slash + 1:], 10, 8)
 			if err != nil {
-				http.Error(w, jsonDNS.FormatError(fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q (%s)", ednsClientSubnet, err.Error())), 400)
+				jsonDNS.FormatError(w, fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q (%s)", ednsClientSubnet, err.Error()), 400)
 				return
 			}
 			ednsClientNetmask = uint8(netmask)
@@ -190,13 +190,13 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 
 	resp, err := s.doDNSQuery(msg)
 	if err != nil {
-		http.Error(w, jsonDNS.FormatError(fmt.Sprintf("DNS query failure (%s)", err.Error())), 503)
+		jsonDNS.FormatError(w, fmt.Sprintf("DNS query failure (%s)", err.Error()), 503)
 		return
 	}
 	respJson := jsonDNS.Marshal(resp)
 	respStr, err := json.Marshal(respJson)
 	if err != nil {
-		http.Error(w, jsonDNS.FormatError(fmt.Sprintf("DNS packet parse failure (%s)", err.Error())), 500)
+		jsonDNS.FormatError(w, fmt.Sprintf("DNS packet parse failure (%s)", err.Error()), 500)
 		return
 	}
 
diff --git a/json-dns/error.go b/json-dns/error.go
index 6f0a79f..d08ff01 100644
--- a/json-dns/error.go
+++ b/json-dns/error.go
@@ -21,6 +21,7 @@ package jsonDNS
 import (
 	"encoding/json"
 	"log"
+	"net/http"
 	"github.com/miekg/dns"
 )
 
@@ -29,7 +30,7 @@ type dnsError struct {
 	Comment				string		`json:"Comment,omitempty"`
 }
 
-func FormatError(comment string) string {
+func FormatError(w http.ResponseWriter, comment string, errcode int) {
 	errJson := dnsError {
 		Status: dns.RcodeServerFailure,
 		Comment: comment,
@@ -38,5 +39,6 @@ func FormatError(comment string) string {
 	if err != nil {
 		log.Fatalln(err)
 	}
-	return string(errStr)
+	w.WriteHeader(errcode)
+	w.Write(errStr)
 }