diff --git a/lib/dragonfly/s3_data_store.rb b/lib/dragonfly/s3_data_store.rb
index bd3e3d4..33ae31f 100644
--- a/lib/dragonfly/s3_data_store.rb
+++ b/lib/dragonfly/s3_data_store.rb
@@ -136,12 +136,15 @@ def full_storage_headers(headers, meta)
     end
 
     def headers_to_meta(headers)
+      meta = {}
       json = headers['x-amz-meta-json']
       if json && !json.empty?
-        unescape_meta_values(Serializer.json_decode(json))
+        meta.merge(unescape_meta_values(Serializer.json_decode(json)))
       elsif marshal_data = headers['x-amz-meta-extra']
-        Utils.stringify_keys(Serializer.marshal_b64_decode(marshal_data))
+        meta.merge(Utils.stringify_keys(Serializer.marshal_b64_decode(marshal_data)))
       end
+      meta['mime_type'] ||= headers['Content-Type'] if headers.key?('Content-Type')
+      meta
     end
 
     def meta_to_headers(meta)