diff --git a/youtube_dl/extractor/bilibili.py b/youtube_dl/extractor/bilibili.py
index 8db8c8c01..2cd26bd70 100644
--- a/youtube_dl/extractor/bilibili.py
+++ b/youtube_dl/extractor/bilibili.py
@@ -101,7 +101,7 @@ class BiliBiliIE(InfoExtractor):
         else:
             raise ExtractorError('Can\'t extract Bangumi episode ID')
 
-    def _getfps(self, s: str) -> int:
+    def _getfps(self, s):
         "convert fps to int"
         if s.isnumeric():
             return int(s)