diff --git a/youtube_dl/extractor/vidzi.py b/youtube_dl/extractor/vidzi.py
index a3ede8627..d70283479 100644
--- a/youtube_dl/extractor/vidzi.py
+++ b/youtube_dl/extractor/vidzi.py
@@ -53,8 +53,9 @@ class VidziIE(InfoExtractor):
             jwplayer_data = self._parse_json(
                 self._search_regex(
                     r'setup\(([^)]+)\)', code, 'jwplayer data',
-                    default=NO_DEFAULT if num == len(codes) else '{}').replace('+ window[\'vastRef\']', ''),
-                video_id, transform_source=js_to_json)
+                    default=NO_DEFAULT if num == len(codes) else '{}'),
+                video_id, transform_source=lambda s: js_to_json(
+                    re.sub(r'\s*\+\s*window\[.+?\]', '', s)))
             if jwplayer_data:
                 break