diff --git a/native_app/src/newgui/hud/windows/load.rs b/native_app/src/newgui/hud/windows/load.rs
index 1c0896b1..a595f0e3 100644
--- a/native_app/src/newgui/hud/windows/load.rs
+++ b/native_app/src/newgui/hud/windows/load.rs
@@ -71,7 +71,7 @@ pub fn load(uiw: &UiWorld, _: &Simulation, opened: &mut bool) {
 
         if let Some(ref mut loading) = uiw.write::<SaveLoadState>().please_load {
             let ticks_done = loading.pastt.0;
-            let ticks_total = loading.replay.commands.last().map(|c| c.0 .0).unwrap_or(0);
+            let ticks_total = loading.replay.last_tick_recorded.0;
             ProgressBar {
                 value: ticks_done as f32 / ticks_total as f32,
                 size: Vec2::new(400.0, 25.0),
diff --git a/simulation/src/lib.rs b/simulation/src/lib.rs
index 43de16ac..5fc61192 100644
--- a/simulation/src/lib.rs
+++ b/simulation/src/lib.rs
@@ -254,6 +254,9 @@ impl Simulation {
 
         game_schedule.execute(self);
 
+        self.resources.write::<Replay>().last_tick_recorded =
+            self.resources.read::<GameTime>().tick;
+
         t.elapsed()
     }
 
diff --git a/simulation/src/tests/test_iso.rs b/simulation/src/tests/test_iso.rs
index a5e25db5..76f9842e 100644
--- a/simulation/src/tests/test_iso.rs
+++ b/simulation/src/tests/test_iso.rs
@@ -267,7 +267,7 @@ fn test_world_survives_serde() {
             "--- tick {} ({}/{})",
             sim.get_tick(),
             loader.pastt.0,
-            loader.replay.commands.last().unwrap().0 .0
+            loader.replay.last_tick_recorded.0
         );
 
         let ser = common::saveload::Bincode::encode(&sim).unwrap();
diff --git a/simulation/src/utils/replay.rs b/simulation/src/utils/replay.rs
index 50120a7d..6f68ba37 100644
--- a/simulation/src/utils/replay.rs
+++ b/simulation/src/utils/replay.rs
@@ -7,7 +7,14 @@ use serde::{Deserialize, Serialize};
 #[derive(Debug, Clone, Default, Serialize, Deserialize)]
 pub struct Replay {
     pub enabled: bool,
-    pub commands: Vec<(Tick, WorldCommand)>,
+    commands: Vec<(Tick, WorldCommand)>,
+    pub last_tick_recorded: Tick,
+}
+
+impl Replay {
+    pub fn push(&mut self, tick: Tick, command: WorldCommand) {
+        self.commands.push((tick, command));
+    }
 }
 
 pub struct SimulationReplayLoader {
@@ -55,7 +62,21 @@ impl SimulationReplayLoader {
             sim.tick(schedule, command_slice.iter().map(|(_, c)| c));
             self.pastt.0 += 1;
             ticks_left -= 1;
+            if ticks_left == 0 {
+                return false;
+            }
+        }
+        if self.idx < self.replay.commands.len() {
+            return false;
+        }
+        while ticks_left > 0 && self.pastt < self.replay.last_tick_recorded {
+            sim.tick(schedule, &[]);
+            self.pastt.0 += 1;
+            ticks_left -= 1;
+            if ticks_left == 0 {
+                return false;
+            }
         }
-        self.idx >= self.replay.commands.len()
+        true
     }
 }
diff --git a/simulation/src/world_command.rs b/simulation/src/world_command.rs
index ba12fd94..7fd98c6f 100644
--- a/simulation/src/world_command.rs
+++ b/simulation/src/world_command.rs
@@ -221,7 +221,7 @@ impl WorldCommand {
         let mut rep = sim.resources.write::<Replay>();
         if rep.enabled {
             let tick = sim.read::<GameTime>().tick;
-            rep.commands.push((tick, self.clone()));
+            rep.push(tick, self.clone());
         }
         drop(rep);
 
@@ -309,7 +309,7 @@ impl WorldCommand {
                     let mut rep = sim.resources.write::<Replay>();
                     rep.enabled = true;
                     let tick = sim.read::<GameTime>().tick;
-                    rep.commands.push((tick, Init(opts.clone())));
+                    rep.push(tick, Init(opts.clone()));
                 }
 
                 if opts.terrain_size > 0 {