diff --git a/src/ivfflat.c b/src/ivfflat.c
index a35f6e8..29ddabb 100644
--- a/src/ivfflat.c
+++ b/src/ivfflat.c
@@ -113,6 +113,7 @@ ivfflatcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 	genericcostestimate(root, path, loop_count, qinfos, &costs);
 #endif
 
+	/* Use total cost since most work happens before first tuple is returned */
 	startupCost = costs.indexTotalCost;
 
 	get_tablespace_page_costs(path->indexinfo->reltablespace, NULL, &spc_seq_page_cost);