--- a/gmime-object.c	2013-12-19 11:47:04.609110566 +0100
+++ b/gmime-object.c	2013-12-19 11:50:02.089519654 +0100
@@ -647,6 +647,7 @@
 	if (!object->disposition) {
 		disposition = g_mime_content_disposition_new ();
 		_g_mime_object_set_content_disposition (object, disposition);
+		g_object_unref(disposition);
 	}
 	
 	g_mime_content_disposition_set_parameter (object->disposition, name, value);