diff --git a/youtube_dl/extractor/dreisat.py b/youtube_dl/extractor/dreisat.py
index b0e4300bd..0b11d1f10 100644
--- a/youtube_dl/extractor/dreisat.py
+++ b/youtube_dl/extractor/dreisat.py
@@ -10,7 +10,7 @@ from ..utils import (
 
 class DreiSatIE(InfoExtractor):
     IE_NAME = '3sat'
-    _VALID_URL = r'(?:http://)?(?:www\.)?3sat\.de/mediathek/index\.php\?(?:(?:mode|display)=[^&]+&)*obj=(?P<id>[0-9]+)$'
+    _VALID_URL = r'(?:http://)?(?:www\.)?3sat\.de/mediathek/(?:index\.php)?\?(?:(?:mode|display)=[^&]+&)*obj=(?P<id>[0-9]+)$'
     _TEST = {
         u"url": u"http://www.3sat.de/mediathek/index.php?obj=36983",
         u'file': u'36983.mp4',