diff --git a/yt_dlp/extractor/cda.py b/yt_dlp/extractor/cda.py
index 2f3d58e0da..49931a0fba 100644
--- a/yt_dlp/extractor/cda.py
+++ b/yt_dlp/extractor/cda.py
@@ -353,7 +353,7 @@ class CDAIE(InfoExtractor):
 
 class CDAFolderIE(InfoExtractor):
     _MAX_PAGE_SIZE = 36
-    _VALID_URL = r'https?://(?:www\.)?cda\.pl/(?P<channel>[a-zA-Z0-9-]+)/folder/(?P<id>\d+)'
+    _VALID_URL = r'https?://(?:www\.)?cda\.pl/(?P<channel>[\w-]+)/folder/(?P<id>\d+)'
     _TESTS = [
         {
             'url': 'https://www.cda.pl/domino264/folder/31188385',