diff --git a/lntest/itest/rest_api.go b/lntest/itest/rest_api.go
index 5eee3d85..c296e3a0 100644
--- a/lntest/itest/rest_api.go
+++ b/lntest/itest/rest_api.go
@@ -201,7 +201,116 @@ func testRestApi(net *lntest.NetworkHarness, ht *harnessTest) {
 				Height: uint32(height),
 			}
 			url := "/v2/chainnotifier/register/blocks"
-			c, err := openWebSocket(a, url, "POST", req)
+			c, err := openWebSocket(a, url, "POST", req, nil)
+			require.Nil(t, err, "websocket")
+			defer func() {
+				_ = c.WriteMessage(
+					websocket.CloseMessage,
+					websocket.FormatCloseMessage(
+						websocket.CloseNormalClosure,
+						"done",
+					),
+				)
+				_ = c.Close()
+			}()
+
+			msgChan := make(chan *chainrpc.BlockEpoch)
+			errChan := make(chan error)
+			timeout := time.After(defaultTimeout)
+
+			// We want to read exactly one message.
+			go func() {
+				defer close(msgChan)
+
+				_, msg, err := c.ReadMessage()
+				if err != nil {
+					errChan <- err
+					return
+				}
+
+				// The chunked/streamed responses come wrapped
+				// in either a {"result":{}} or {"error":{}}
+				// wrapper which we'll get rid of here.
+				msgStr := string(msg)
+				if !strings.Contains(msgStr, "\"result\":") {
+					errChan <- fmt.Errorf("invalid msg: %s",
+						msgStr)
+					return
+				}
+				msgStr = resultPattern.ReplaceAllString(
+					msgStr, "${1}",
+				)
+
+				// Make sure we can parse the unwrapped message
+				// into the expected proto message.
+				protoMsg := &chainrpc.BlockEpoch{}
+				err = jsonpb.UnmarshalString(
+					msgStr, protoMsg,
+				)
+				if err != nil {
+					errChan <- err
+					return
+				}
+
+				select {
+				case msgChan <- protoMsg:
+				case <-timeout:
+				}
+			}()
+
+			// Mine a block and make sure we get a message for it.
+			blockHashes, err := net.Miner.Node.Generate(1)
+			require.Nil(t, err, "generate blocks")
+			assert.Equal(t, 1, len(blockHashes), "num blocks")
+			select {
+			case msg := <-msgChan:
+				assert.Equal(
+					t, blockHashes[0].CloneBytes(),
+					msg.Hash, "block hash",
+				)
+
+			case err := <-errChan:
+				t.Fatalf("Received error from WS: %v", err)
+
+			case <-timeout:
+				t.Fatalf("Timeout before message was received")
+			}
+		},
+	}, {
+		name: "websocket subscription with macaroon in protocol",
+		run: func(t *testing.T, a, b *lntest.HarnessNode) {
+			// Find out the current best block so we can subscribe
+			// to the next one.
+			hash, height, err := net.Miner.Node.GetBestBlock()
+			require.Nil(t, err, "get best block")
+
+			// Create a new subscription to get block epoch events.
+			req := &chainrpc.BlockEpoch{
+				Hash:   hash.CloneBytes(),
+				Height: uint32(height),
+			}
+			url := "/v2/chainnotifier/register/blocks"
+
+			// This time we send the macaroon in the special header
+			// Sec-Websocket-Protocol which is the only header field
+			// available to browsers when opening a WebSocket.
+			mac, err := a.ReadMacaroon(
+				a.AdminMacPath(), defaultTimeout,
+			)
+			require.NoError(t, err, "read admin mac")
+			macBytes, err := mac.MarshalBinary()
+			require.NoError(t, err, "marshal admin mac")
+
+			customHeader := make(http.Header)
+			customHeader.Set(
+				lnrpc.HeaderWebSocketProtocol, fmt.Sprintf(
+					"Grpc-Metadata-Macaroon+%s",
+					hex.EncodeToString(macBytes),
+				),
+			)
+			c, err := openWebSocket(
+				a, url, "POST", req, customHeader,
+			)
 			require.Nil(t, err, "websocket")
 			defer func() {
 				_ = c.WriteMessage(
@@ -364,14 +473,17 @@ func makeRequest(node *lntest.HarnessNode, url, method string,
 // openWebSocket opens a new WebSocket connection to the given URL with the
 // appropriate macaroon headers and sends the request message over the socket.
 func openWebSocket(node *lntest.HarnessNode, url, method string,
-	req proto.Message) (*websocket.Conn, error) {
+	req proto.Message, customHeader http.Header) (*websocket.Conn, error) {
 
 	// Prepare our macaroon headers and assemble the full URL from the
 	// node's listening address. WebSockets always work over GET so we need
 	// to append the target request method as a query parameter.
-	header := make(http.Header)
-	if err := addAdminMacaroon(node, header); err != nil {
-		return nil, err
+	header := customHeader
+	if header == nil {
+		header = make(http.Header)
+		if err := addAdminMacaroon(node, header); err != nil {
+			return nil, err
+		}
 	}
 	fullURL := fmt.Sprintf(
 		"wss://%s%s?method=%s", node.Cfg.RESTAddr(), url, method,