diff --git a/youtube_dl/extractor/cwtv.py b/youtube_dl/extractor/cwtv.py
index f9bd535f6..73382431b 100644
--- a/youtube_dl/extractor/cwtv.py
+++ b/youtube_dl/extractor/cwtv.py
@@ -79,7 +79,7 @@ class CWTVIE(InfoExtractor):
         season = str_or_none(video_data.get('season'))
         episode = str_or_none(video_data.get('episode'))
         if episode and season:
-            episode = episode.lstrip(season)
+            episode = episode[len(season):]
 
         return {
             '_type': 'url_transparent',