diff --git a/youtube_dl/extractor/spankbang.py b/youtube_dl/extractor/spankbang.py
index 9277ab825..a2f7af648 100644
--- a/youtube_dl/extractor/spankbang.py
+++ b/youtube_dl/extractor/spankbang.py
@@ -112,7 +112,7 @@ class SpankBangIE(InfoExtractor):
                     if format_url and isinstance(format_url, list):
                         format_url = format_url[0]
                     extract_format(
-                        format_id[len(STREAM_URL_PREFIX):], format_url)
+                        format_id, format_url)
 
         self._sort_formats(formats)