diff --git a/src/particle_restart.cpp b/src/particle_restart.cpp
index e0295ceb5a..f7159ce444 100644
--- a/src/particle_restart.cpp
+++ b/src/particle_restart.cpp
@@ -95,13 +95,11 @@ void run_particle_restart()
   int64_t particle_seed;
   switch (previous_run_mode) {
   case RunMode::EIGENVALUE:
+  case RunMode::FIXED_SOURCE:
     particle_seed = (simulation::total_gen + overall_generation() - 1) *
                       settings::n_particles +
                     p.id();
     break;
-  case RunMode::FIXED_SOURCE:
-    particle_seed = p.id();
-    break;
   default:
     throw std::runtime_error {
       "Unexpected run mode: " +
diff --git a/src/simulation.cpp b/src/simulation.cpp
index e29c4da25f..35d76ed874 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -679,6 +679,8 @@ void transport_history_based_single_particle(Particle& p)
 {
   while (true) {
     p.event_calculate_xs();
+    if (!p.alive())
+      break;
     p.event_advance();
     if (p.collision_distance() > p.boundary().distance) {
       p.event_cross_surface();