diff --git a/builtin/commit.c b/builtin/commit.c
index da1ba4c..7587810 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1809,7 +1809,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		cfg = init_copy_notes_for_rewrite("amend");
 		if (cfg) {
 			/* we are amending, so current_head is not NULL */
-			copy_note_for_rewrite(cfg, current_head->object.oid.hash, oid.hash);
+			copy_note_for_rewrite(cfg, &current_head->object.oid, &oid);
 			finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
 		}
 		run_rewrite_hook(&current_head->object.oid, &oid);