thodg/got

diff --git a/lib/object.c b/lib/object.c
index 1cd78bd..6ad23fc 100644
--- a/lib/object.c
+++ b/lib/object.c
@@ -701,6 +701,7 @@ got_object_tree_open(struct got_tree_object **tree,
 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
 		if (err)
 			return err;
+		len -= obj->hdrlen;
 		err = parse_tree_object(tree, repo, buf + obj->hdrlen, len);
 		free(buf);
 	} else {