diff --git a/http2/server.go b/http2/server.go
index 5e2583c..2d859af 100644
--- a/http2/server.go
+++ b/http2/server.go
@@ -2677,6 +2677,14 @@ func (rws *responseWriterState) writeHeader(code int) {
 		// Per RFC 8297 we must not clear the current header map
 		h := rws.handlerHeader
 
+		_, cl := h["Content-Length"]
+		_, te := h["Transfer-Encoding"]
+		if cl || te {
+			h = h.Clone()
+			h.Del("Content-Length")
+			h.Del("Transfer-Encoding")
+		}
+
 		if rws.conn.writeHeaders(rws.stream, &writeResHeaders{
 			streamID:    rws.stream.id,
 			httpResCode: code,
diff --git a/http2/server_test.go b/http2/server_test.go
index ef5ad5b..9caf713 100644
--- a/http2/server_test.go
+++ b/http2/server_test.go
@@ -4392,6 +4392,7 @@ func TestServerSendsProcessing(t *testing.T) {
 func TestServerSendsEarlyHints(t *testing.T) {
 	testServerResponse(t, func(w http.ResponseWriter, r *http.Request) error {
 		h := w.Header()
+		h.Add("Content-Length", "123")
 		h.Add("Link", "</style.css>; rel=preload; as=style")
 		h.Add("Link", "</script.js>; rel=preload; as=script")
 		w.WriteHeader(http.StatusEarlyHints)
@@ -4437,7 +4438,7 @@ func TestServerSendsEarlyHints(t *testing.T) {
 			{"link", "</script.js>; rel=preload; as=script"},
 			{"link", "</foo.js>; rel=preload; as=script"},
 			{"content-type", "text/plain; charset=utf-8"},
-			{"content-length", "5"},
+			{"content-length", "123"},
 		}
 
 		if !reflect.DeepEqual(goth, wanth) {