diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index ebad09ea6..688f338fb 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -6,9 +6,11 @@ django-storages change log
 
 * Files uploaded with ``GoogleCloudStorage`` will now set their appropriate mimetype (`#320`_)
 * Fix ``DropBoxStorage.url`` to work. (`#357`_)
+* Fix ``S3Boto3Storage`` when ``AWS_PRELOAD_METADATA = True`` (`#366`_)
 
 .. _#320: https://github.com/jschneier/django-storages/pull/320
 .. _#357: https://github.com/jschneier/django-storages/pull/357
+.. _#366: https://github.com/jschneier/django-storages/pull/366
 
 1.6.3 (2017-06-23)
 ******************
diff --git a/storages/backends/s3boto3.py b/storages/backends/s3boto3.py
index 741bf3333..97cd6294d 100644
--- a/storages/backends/s3boto3.py
+++ b/storages/backends/s3boto3.py
@@ -487,7 +487,7 @@ def size(self, name):
         if self.entries:
             entry = self.entries.get(name)
             if entry:
-                return entry.content_length
+                return entry.size
             return 0
         return self.bucket.Object(self._encode_name(name)).content_length