diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index e80a2dad0b..7cbd846f60 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -390,6 +390,10 @@ class InfoExtractor(object):
             url_or_request, video_id, note, errnote, fatal=fatal)
         if (not fatal) and json_string is False:
             return None
+        return self._parse_json(
+            json_string, video_id, transform_source=transform_source, fatal=fatal)
+
+    def _parse_json(self, json_string, video_id, transform_source=None, fatal=True):
         if transform_source:
             json_string = transform_source(json_string)
         try: