diff --git a/test/ComponentTest.cs b/test/ComponentTest.cs
index e881f64..fadb126 100644
--- a/test/ComponentTest.cs
+++ b/test/ComponentTest.cs
@@ -26,7 +26,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var entityMessage in ReadMessages<EntityMessage>())
+                foreach (ref readonly var entityMessage in ReadMessages<EntityMessage>())
                 {
                     gottenMockComponent = GetComponent<MockComponent>(entityMessage.entity);
                 }
@@ -207,7 +207,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var message in ReadMessages<AddMockComponentMessage>())
+                foreach (ref readonly var message in ReadMessages<AddMockComponentMessage>())
                 {
                     SetComponent(message.entity, message.mockComponent);
                 }
@@ -280,7 +280,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var hasComponentTestEngine in ReadMessages<HasComponentTestMessage>())
+                foreach (ref readonly var hasComponentTestEngine in ReadMessages<HasComponentTestMessage>())
                 {
                     Assert.IsTrue(HasComponent<MockComponent>(hasComponentTestEngine.entity));
                 }
@@ -317,7 +317,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var hasComponentTestEngine in ReadMessages<HasComponentTestMessage>())
+                foreach (ref readonly var hasComponentTestEngine in ReadMessages<HasComponentTestMessage>())
                 {
                     hasComponentRuntimeTypeResult = HasComponent(hasComponentTestEngine.entity, typeof(MockComponent));
                 }
@@ -379,7 +379,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var removeComponentMessage in ReadMessages<RemoveComponentTestMessage>())
+                foreach (ref readonly var removeComponentMessage in ReadMessages<RemoveComponentTestMessage>())
                 {
                     RemoveComponent<MockComponent>(removeComponentMessage.entity);
                 }
@@ -424,7 +424,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var checkHasMockComponentMessage in ReadMessages<CheckHasMockComponentMessage>())
+                foreach (ref readonly var checkHasMockComponentMessage in ReadMessages<CheckHasMockComponentMessage>())
                 {
                     hasComponentResult = HasComponent<MockComponent>(checkHasMockComponentMessage.entity);
                 }
@@ -473,7 +473,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var checkHasMockComponentMessage in ReadMessages<CheckHasMockComponentMessage>())
+                foreach (ref readonly var checkHasMockComponentMessage in ReadMessages<CheckHasMockComponentMessage>())
                 {
                     Assert.IsTrue(HasComponent<MockComponent>(checkHasMockComponentMessage.entity));
                 }
diff --git a/test/EngineTest.cs b/test/EngineTest.cs
index dd4d7d6..5c2d2d6 100644
--- a/test/EngineTest.cs
+++ b/test/EngineTest.cs
@@ -683,7 +683,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var message in ReadMessages<DestroyComponentMessage>())
+                foreach (ref readonly var message in ReadMessages<DestroyComponentMessage>())
                 {
                     Destroy(message.entity);
                 }
@@ -879,7 +879,7 @@ namespace Tests
         {
             public override void Update(double dt)
             {
-                foreach (var message in ReadMessages<MockMessage>())
+                foreach (ref readonly var message in ReadMessages<MockMessage>())
                 {
                     var entity = CreateEntity();
                     SetComponent(entity, new MockComponent { });
diff --git a/test/WorldBuilderTest.cs b/test/WorldBuilderTest.cs
index 68b333b..871dce4 100644
--- a/test/WorldBuilderTest.cs
+++ b/test/WorldBuilderTest.cs
@@ -159,7 +159,7 @@ namespace Tests
             {
                 public override void Update(double dt)
                 {
-                    foreach (var setMessage in ReadMessages<SetMessage>())
+                    foreach (ref readonly var setMessage in ReadMessages<SetMessage>())
                     {
                         SetComponent(setMessage.entity, new AComponent { myInt = 0 });
                     }
@@ -173,7 +173,7 @@ namespace Tests
             {
                 public override void Update(double dt)
                 {
-                    foreach (var setMessage in ReadMessages<SetMessage>())
+                    foreach (ref readonly var setMessage in ReadMessages<SetMessage>())
                     {
                         SetComponent(setMessage.entity, new AComponent { myInt = 1 });
                     }
@@ -229,7 +229,7 @@ namespace Tests
             {
                 public override void Update(double dt)
                 {
-                    foreach (var setMessage in ReadMessages<SetMessage>())
+                    foreach (ref readonly var setMessage in ReadMessages<SetMessage>())
                     {
                         SetComponent(setMessage.entity, new AComponent { myInt = 5 });
                     }
@@ -244,7 +244,7 @@ namespace Tests
             {
                 public override void Update(double dt)
                 {
-                    foreach (var setMessage in ReadMessages<SetMessage>())
+                    foreach (ref readonly var setMessage in ReadMessages<SetMessage>())
                     {
                         SetComponent(setMessage.entity, new AComponent { myInt = 1 });
                     }
@@ -258,7 +258,7 @@ namespace Tests
             {
                 public override void Update(double dt)
                 {
-                    foreach (var setMessage in ReadMessages<SetMessage>())
+                    foreach (ref readonly var setMessage in ReadMessages<SetMessage>())
                     {
                         SetComponent(setMessage.entity, new AComponent { myInt = 3 });
                     }