diff --git a/instaloader/structures.py b/instaloader/structures.py
index 4a7d0b2..aef7e8e 100644
--- a/instaloader/structures.py
+++ b/instaloader/structures.py
@@ -128,7 +128,7 @@ class Post:
             pic_json = self._context.get_json("p/{0}/".format(self.shortcode), params={})
             self._full_metadata_dict = pic_json['entry_data']['PostPage'][0]['graphql']['shortcode_media']
             self._rhx_gis_str = pic_json['rhx_gis']
-            if self.mediaid != self._full_metadata_dict['id']:
+            if self.shortcode != self._full_metadata_dict['shortcode']:
                 self._node.update(self._full_metadata_dict)
                 raise PostChangedException