diff --git a/youtube_dl/downloader/youtube_live_chat.py b/youtube_dl/downloader/youtube_live_chat.py
index 214a37203..e7eb4bbfe 100644
--- a/youtube_dl/downloader/youtube_live_chat.py
+++ b/youtube_dl/downloader/youtube_live_chat.py
@@ -28,7 +28,7 @@ class YoutubeLiveChatReplayFD(FragmentFD):
             return self._download_fragment(ctx, url, info_dict, headers)
 
         def parse_yt_initial_data(data):
-            raw_json = re.search(rb'window\["ytInitialData"\]\s*=\s*(.*);', data).group(1)
+            raw_json = re.search(b'window\\["ytInitialData"\\]\s*=\\s*(.*);', data).group(1)
             return json.loads(raw_json)
 
         self._prepare_and_start_frag_download(ctx)