diff --git a/src/hb-ot-layout-common.hh b/src/hb-ot-layout-common.hh
index 23d5279a3..3c621d715 100644
--- a/src/hb-ot-layout-common.hh
+++ b/src/hb-ot-layout-common.hh
@@ -1762,7 +1762,7 @@ struct VarData
       {
 	unsigned int old = remap.to_old (i);
 	if (unlikely (old >= src->itemCount)) return_trace (false);
-	int16_t delta = get_item_delta (old, short_count - 1);
+	int16_t delta = src->get_item_delta (old, short_count - 1);
 	if (delta < -128 || 127 < delta) goto found_short;
       }