diff --git a/fetch-pack.c b/fetch-pack.c
index 105506e..008b25d 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -611,7 +611,7 @@ static int tip_oids_contain(struct oidset *tip_oids,
 	 * add to "newlist" between calls, the additions will always be for
 	 * oids that are already in the set.
 	 */
-	if (!tip_oids->map.tablesize) {
+	if (!tip_oids->map.map.tablesize) {
 		add_refs_to_oidset(tip_oids, unmatched);
 		add_refs_to_oidset(tip_oids, newlist);
 	}