diff --git a/src/hb-ot-var-gvar-table.hh b/src/hb-ot-var-gvar-table.hh
index 31970458d..77d6ab47d 100644
--- a/src/hb-ot-var-gvar-table.hh
+++ b/src/hb-ot-var-gvar-table.hh
@@ -609,8 +609,8 @@ struct gvar
 	{
 	  unsigned int pt_index = apply_to_all ? i : indices[i];
 	  deltas[pt_index].flag = 1;	/* this point is referenced, i.e., explicit deltas specified */
-	  deltas[pt_index].x += x_deltas[i] * scalar;
-	  deltas[pt_index].y += y_deltas[i] * scalar;
+	  deltas[pt_index].x += x_deltas.arrayZ[i] * scalar;
+	  deltas[pt_index].y += y_deltas.arrayZ[i] * scalar;
 	}
 
 	/* infer deltas for unreferenced points */