diff --git a/youtube_dl/downloader/f4m.py b/youtube_dl/downloader/f4m.py
index f478fc03cd..174180db5b 100644
--- a/youtube_dl/downloader/f4m.py
+++ b/youtube_dl/downloader/f4m.py
@@ -13,6 +13,8 @@ from ..compat import (
     compat_urllib_error,
 )
 from ..utils import (
+    encodeFilename,
+    sanitize_open,
     struct_pack,
     struct_unpack,
     xpath_text,