@@ -412,7 +412,10 @@ class S3(object):

         content_type = self.config.mime_type

         content_encoding = None

         if filename != "-" and not content_type and self.config.guess_mime_type:

-            (content_type, content_encoding) = mime_magic(filename) if self.config.use_mime_magic else mimetypes.guess_type(filename)

+            if self.config.use_mime_magic:

+                (content_type, content_encoding) = mime_magic(filename)

+            else:

+                (content_type, content_encoding) = mimetypes.guess_type(filename)

         if not content_type:

             content_type = self.config.default_mime_type