diff --git a/youtube_dl/extractor/reddit.py b/youtube_dl/extractor/reddit.py
index 505442332..8372925be 100644
--- a/youtube_dl/extractor/reddit.py
+++ b/youtube_dl/extractor/reddit.py
@@ -47,7 +47,7 @@ class RedditIE(InfoExtractor):
 
 
 class RedditRIE(InfoExtractor):
-    _VALID_URL = r'(?P<url>https?://(?:www\.|old\.)?reddit\.com/r/[^/]+/comments/(?P<id>[^/?#&]+))'
+    _VALID_URL = r'(?P<url>https?://(?:(?:www|old)\.)?reddit\.com/r/[^/]+/comments/(?P<id>[^/?#&]+))'
     _TESTS = [{
         'url': 'https://www.reddit.com/r/videos/comments/6rrwyj/that_small_heart_attack/',
         'info_dict': {