diff --git a/src/Murder/Data/Save/BlackboardTracker.cs b/src/Murder/Data/Save/BlackboardTracker.cs
index bcc96853..95d1f1e0 100644
--- a/src/Murder/Data/Save/BlackboardTracker.cs
+++ b/src/Murder/Data/Save/BlackboardTracker.cs
@@ -16,6 +16,7 @@ namespace Murder.Save
     /// <summary>
     /// Track variables that contain the state of the world.
     /// </summary>
+    [Serializable]
     public class BlackboardTracker
     {
         [Serialize]