diff --git a/common/route/router2.cc b/common/route/router2.cc
index 49fe327a..d592dcb8 100644
--- a/common/route/router2.cc
+++ b/common/route/router2.cc
@@ -782,7 +782,7 @@ struct Router2
                         next_score.delay = curr.score.delay + cfg.get_base_cost(ctx, next, uh, crit_weight);
                         next_score.cost = curr.score.cost + score_wire_for_arc(net, i, phys_pin, next, uh, crit_weight);
                         next_score.togo_cost =
-                                cfg.estimate_weight * get_togo_cost(net, i, next_idx, src_wire, true, crit_weight);
+                                const_mode ? 0 : cfg.estimate_weight * get_togo_cost(net, i, next_idx, src_wire, true, crit_weight);
                         if (was_visited_bwd(next_idx, next_score.delay)) {
                             // Don't expand the same node twice.
                             continue;