diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index 9b0016d07..78704b557 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -3170,7 +3170,7 @@ class InfoExtractor(object):
                     # See com/longtailvideo/jwplayer/media/RTMPMediaProvider.as
                     # of jwplayer.flash.swf
                     rtmp_url_parts = re.split(
-                        r'((?:mp4|mp3|flv):)', source_url, 1)
+                        r'((?:mp4|mp3|flv):)', source_url, maxsplit=1)
                     if len(rtmp_url_parts) == 3:
                         rtmp_url, prefix, play_path = rtmp_url_parts
                         a_format.update({