diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 7069f60..06870a3 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -1639,7 +1639,8 @@ cost_agg(Path *path, PlannerInfo *root,
 	else
 	{
 		/* must be AGG_HASHED */
-		startup_cost = input_total_cost;
+		startup_cost = input_startup_cost;
+		startup_cost += input_total_cost;
 		startup_cost += aggcosts->transCost.startup;
 		startup_cost += aggcosts->transCost.per_tuple * input_tuples;
 		startup_cost += (cpu_operator_cost * numGroupCols) * input_tuples;