diff --git a/src/net/http/server.go b/src/net/http/server.go
index dbd629210e1e4541d86bf3209f15b1c2db5ebce5..33588609b102b4a533ef828d936bfe1056d8dbd3 100644
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -1326,6 +1326,7 @@ func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
 // The error message should be plain text.
 func Error(w ResponseWriter, error string, code int) {
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.WriteHeader(code)
 	fmt.Fprintln(w, error)
 }