diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index 0bbb1103b..74b6f1197 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -2205,8 +2205,9 @@ def _extract_akamai_formats(self, manifest_url, video_id, hosts={}):
 
     def _extract_wowza_formats(self, url, video_id, m3u8_entry_protocol='m3u8_native', skip_protocols=[]):
         url = re.sub(r'/(?:manifest|playlist|jwplayer)\.(?:m3u8|f4m|mpd|smil)', '', url)
-        url_base = self._search_regex(r'(?:https?|rtmp|rtsp)(://[^?]+)', url, 'format url')
-        http_base_url = 'http' + url_base
+        url_base = self._search_regex(
+            r'(?:(?:https?|rtmp|rtsp):)?(//[^?]+)', url, 'format url')
+        http_base_url = self._proto_relative_url(url_base, scheme='http:')
         formats = []
         if 'm3u8' not in skip_protocols:
             formats.extend(self._extract_m3u8_formats(