diff --git a/dashproxy.py b/dashproxy.py
index 5482ef6..c6e78fc 100755
--- a/dashproxy.py
+++ b/dashproxy.py
@@ -259,7 +259,7 @@ def full_url(self, dest):
         return self.mpd_base_url + dest # TODO remove hardcoded arrd
 
     def write(self, dest, content):
-        dest = dest[0:dest.rfind('?')]
+        dest = dest.split('?')[0]
         dest = os.path.join(self.proxy.output_dir, dest)
         f = open(dest, 'wb')
         f.write(content)