diff --git a/encompass-cs/WorldBuilder.cs b/encompass-cs/WorldBuilder.cs
index 2d1157d..b4cd02f 100644
--- a/encompass-cs/WorldBuilder.cs
+++ b/encompass-cs/WorldBuilder.cs
@@ -55,46 +55,38 @@ namespace Encompass
                 entityManager.RegisterEntityTracker(engine as IEntityTracker);
             }
 
-            var emitMessageAttribute = engine.GetType().GetCustomAttribute<Emits>(false);
-            if (emitMessageAttribute != null)
+            foreach (var emitMessageType in engine.emitMessageTypes)
             {
-                foreach (var emitMessageType in engine.GetType().GetCustomAttribute<Emits>(false).emitMessageTypes)
+                if (!messageTypeToEmitters.ContainsKey(emitMessageType))
                 {
-                    if (!messageTypeToEmitters.ContainsKey(emitMessageType))
-                    {
-                        messageTypeToEmitters.Add(emitMessageType, new HashSet<Engine>());
-                    }
+                    messageTypeToEmitters.Add(emitMessageType, new HashSet<Engine>());
+                }
 
-                    messageTypeToEmitters[emitMessageType].Add(engine);
+                messageTypeToEmitters[emitMessageType].Add(engine);
 
-                    if (messageTypeToReaders.ContainsKey(emitMessageType))
+                if (messageTypeToReaders.ContainsKey(emitMessageType))
+                {
+                    foreach (var reader in messageTypeToReaders[emitMessageType])
                     {
-                        foreach (var reader in messageTypeToReaders[emitMessageType])
-                        {
-                            engineGraph.AddEdge(engine, reader);
-                        }
+                        engineGraph.AddEdge(engine, reader);
                     }
                 }
             }
 
-            var readMessageAttribute = engine.GetType().GetCustomAttribute<Reads>(false);
-            if (readMessageAttribute != null)
+            foreach (var readMessageType in engine.readMessageTypes)
             {
-                foreach (var readMessageType in engine.GetType().GetCustomAttribute<Reads>(false).readMessageTypes)
+                if (!messageTypeToReaders.ContainsKey(readMessageType))
                 {
-                    if (!messageTypeToReaders.ContainsKey(readMessageType))
-                    {
-                        messageTypeToReaders.Add(readMessageType, new HashSet<Engine>());
-                    }
+                    messageTypeToReaders.Add(readMessageType, new HashSet<Engine>());
+                }
 
-                    messageTypeToReaders[readMessageType].Add(engine);
+                messageTypeToReaders[readMessageType].Add(engine);
 
-                    if (messageTypeToEmitters.ContainsKey(readMessageType))
+                if (messageTypeToEmitters.ContainsKey(readMessageType))
+                {
+                    foreach (var emitter in messageTypeToEmitters[readMessageType])
                     {
-                        foreach (var emitter in messageTypeToEmitters[readMessageType])
-                        {
-                            engineGraph.AddEdge(emitter, engine);
-                        }
+                        engineGraph.AddEdge(emitter, engine);
                     }
                 }
             }
diff --git a/test/SpawnerTest.cs b/test/SpawnerTest.cs
index d4a3ce0..ed924d2 100644
--- a/test/SpawnerTest.cs
+++ b/test/SpawnerTest.cs
@@ -14,6 +14,15 @@ namespace Tests
 
         static Entity resultEntity;
 
+        [Emits(typeof(SpawnMessageA))]
+        class MessageEmitter : Engine
+        {
+            public override void Update(double dt)
+            {
+                EmitMessage(new SpawnMessageA());
+            }
+        }
+
         class TestSpawner : Spawner<SpawnMessageA>
         {
             protected override void Spawn(SpawnMessageA message)
@@ -27,10 +36,9 @@ namespace Tests
         public void RunsSpawnMethodOnMessageRead()
         {
             var worldBuilder = new WorldBuilder();
+            worldBuilder.AddEngine(new MessageEmitter());
             worldBuilder.AddEngine(new TestSpawner());
 
-            worldBuilder.EmitMessage(new SpawnMessageA());
-
             var world = worldBuilder.Build();
 
             world.Update(0.01);
@@ -41,7 +49,7 @@ namespace Tests
 
             world.Update(0.01);
 
-            Assert.That(resultEntity.id, Is.EqualTo(id));
+            Assert.That(resultEntity.id, Is.Not.EqualTo(id));
         }
     }
 }