diff --git a/src/Unity/Assets/Scripts/Managers/SimulationRunner.cs b/src/Unity/Assets/Scripts/Managers/SimulationRunner.cs
index 26f1ffa..6a2adbe 100644
--- a/src/Unity/Assets/Scripts/Managers/SimulationRunner.cs
+++ b/src/Unity/Assets/Scripts/Managers/SimulationRunner.cs
@@ -28,6 +28,7 @@ namespace CounterDrone.Unity
 
         private readonly Dictionary<string, GameObject> _entityVisuals = new();
         private readonly Dictionary<string, GameObject> _clouds = new();
+        private readonly HashSet<string> _knownMunitions = new();
 
         public SimulationEngine Engine => _engine;