diff --git a/beets/autotag/mb.py b/beets/autotag/mb.py
index 804a37db8..d1ac7956d 100644
--- a/beets/autotag/mb.py
+++ b/beets/autotag/mb.py
@@ -596,7 +596,7 @@ def album_info(release: Dict) -> beets.autotag.hooks.AlbumInfo:
     # Media (format).
     if release["medium-list"]:
         # If all media are the same, use that medium name
-        if len(set([x.get("format") for x in release["medium-list"]])) == 1:
+        if len(set([m.get("format") for m in release["medium-list"]])) == 1:
             info.media = release["medium-list"][0].get("format")
         # Otherwise, let's just call it "Media"
         else:
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 798f5726c..72186603d 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -292,8 +292,9 @@ Bug fixes:
   and caching in `zsh`.
   :bug:`3546`
 * Remove unused functions :bug:`5103`
-* Fix bug where all media types are reported as the first media type
-  :bug:`5134`
+* Fix bug where all media types are reported as the first media type when
+  importing with MusicBrainz as the data source
+  :bug:`4947`
 
 For plugin developers: