diff --git a/Libraries/WebSocket/WebSocket.js b/Libraries/WebSocket/WebSocket.js
index 3fdde2b3639adf..c544e185ecd129 100644
--- a/Libraries/WebSocket/WebSocket.js
+++ b/Libraries/WebSocket/WebSocket.js
@@ -245,7 +245,12 @@ class WebSocket extends (EventTarget(...WEBSOCKET_EVENTS): any) {
             data = BlobManager.createFromOptions(ev.data);
             break;
         }
-        this.dispatchEvent(new WebSocketEvent('message', {data}));
+        const raw_length = ev.raw_length;
+        if (raw_length == null) {
+          this.dispatchEvent(new WebSocketEvent('message', {data}));
+        } else {
+          this.dispatchEvent(new WebSocketEvent('message', {data, raw_length}));
+        }
       }),
       this._eventEmitter.addListener('websocketOpen', ev => {
         if (ev.id !== this._socketId) {