Fix predefined 404 Content-Type

2 files changed, 15 insertions, 5 deletions

diff --git a/404.go b/404.go
index 3634ddf0..0ac0be54 100644
--- a/404.go
+++ b/404.go
@@ -1,8 +1,8 @@
 package main
 
 import (
-	"net/http"
 	"fmt"
+	"net/http"
 )
 
 const predefined404 = `
@@ -63,7 +63,7 @@ const predefined404 = `
 `
 
 func serve404(w http.ResponseWriter) {
-	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.WriteHeader(http.StatusNotFound)
 	fmt.Fprintln(w, predefined404)
diff --git a/domain_test.go b/domain_test.go
index 56e032a4..9032aeee 100644
--- a/domain_test.go
+++ b/domain_test.go
@@ -2,12 +2,12 @@ package main
 
 import (
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"mime"
 	"net/http"
+	"net/http/httptest"
 	"net/url"
 	"testing"
-	"net/http/httptest"
-	"github.com/stretchr/testify/require"
-	"mime"
 )
 
 func TestGroupServeHTTP(t *testing.T) {
@@ -95,6 +95,16 @@ func TestDomain404ServeHTTP(t *testing.T) {
 	testHTTP404(t, testDomain.ServeHTTP, "GET", "http://group.404.test.io/", nil, "Custom 404 group page")
 }
 
+func TestPredefined404ServeHTTP(t *testing.T) {
+	setUpTests()
+
+	testDomain := &domain{
+		Group: "group",
+	}
+
+	testHTTP404(t, testDomain.ServeHTTP, "GET", "http://group.test.io/not-existing-file", nil, "The page you're looking for could not be found")
+}
+
 func TestGroupCertificate(t *testing.T) {
 	testGroup := &domain{
 		Group:   "group",