diff --git a/beets/mediafile.py b/beets/mediafile.py
index 8f733ccbd..0ff1239ec 100644
--- a/beets/mediafile.py
+++ b/beets/mediafile.py
@@ -985,7 +985,7 @@ class MediaFile(object):
         imprecision is possible because the file header is incorporated
         in the file size.
         """
-        if hasattr(self.mgfile.info, 'bitrate'):
+        if hasattr(self.mgfile.info, 'bitrate') and self.mgfile.info.bitrate:
             # Many formats provide it explicitly.
             return self.mgfile.info.bitrate
         else:
diff --git a/docs/changelog.rst b/docs/changelog.rst
index f821ea13a..9cd3cdba5 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -36,6 +36,8 @@ Changelog
   "OR" (upper case).
 * Fix an error in the ``rewrite`` and ``inline`` plugins when the corresponding
   config sections did not exist.
+* Fix bitrate estimation for AAC files whose headers are missing the relevant
+  data.
 
 1.0b12 (January 16, 2012)
 -------------------------