diff --git a/src/build.cc b/src/build.cc
index 7ad08117be..66ec2cb5b0 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -468,7 +468,9 @@ namespace {
 // Heuristic for edge priority weighting.
 // Phony edges are free (0 cost), all other edges are weighted equally.
 int64_t EdgeWeightHeuristic(Edge *edge) {
-  return edge->is_phony() ? 0 : 1;
+  int64_t prev_elapsed_time_millis =
+    edge->prev_elapsed_time_millis < 0 ? 1 : edge->prev_elapsed_time_millis;
+  return edge->is_phony() ? 0 : prev_elapsed_time_millis;
 }
 
 }  // namespace