diff --git a/encompass-cs/MessageManager.cs b/encompass-cs/MessageManager.cs
index 5cadf61..f143946 100644
--- a/encompass-cs/MessageManager.cs
+++ b/encompass-cs/MessageManager.cs
@@ -1,3 +1,4 @@
+using System.Collections.Concurrent;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -6,12 +7,12 @@ namespace Encompass
 {
     internal class MessageManager
     {
-        private readonly Dictionary<Type, List<IMessage>> messageTypeToMessages = new Dictionary<Type, List<IMessage>>();
+        private readonly Dictionary<Type, ConcurrentStack<IMessage>> messageTypeToMessages = new Dictionary<Type, ConcurrentStack<IMessage>>();
 
         internal void RegisterMessageType(Type messageType)
         {
             if (!messageTypeToMessages.ContainsKey(messageType)) {
-                messageTypeToMessages.Add(messageType, new List<IMessage>());
+                messageTypeToMessages.Add(messageType, new ConcurrentStack<IMessage>());
             }
         }
 
@@ -19,12 +20,12 @@ namespace Encompass
         {
             var type = message.GetType();
 
-            messageTypeToMessages[type].Add(message);
+            messageTypeToMessages[type].Push(message);
         }
 
         internal void AddMessage<TMessage>(TMessage message) where TMessage : struct, IMessage
         {
-            messageTypeToMessages[typeof(TMessage)].Add(message);
+            messageTypeToMessages[typeof(TMessage)].Push(message);
         }
 
         internal void ClearMessages()