diff --git a/ydl/yt_dlp.py b/ydl/yt_dlp.py
index d7a9ec4..68d54c6 100644
--- a/ydl/yt_dlp.py
+++ b/ydl/yt_dlp.py
@@ -29,7 +29,7 @@ class YDL:
                 sizes.append(d)
         return tuple(sizes)
 
-    def playlist_contents(self, url: str) -> dict | bool:
+    def playlist_contents(self, url: str) -> Union[dict, bool]:
         ydl_opts = merge({
             'extract_flat': True,
             'skip_download': True