diff --git a/Terminal.Gui/View/Orientation/IOrientation.cs b/Terminal.Gui/View/Orientation/IOrientation.cs
index 34470878e..c5a7c115f 100644
--- a/Terminal.Gui/View/Orientation/IOrientation.cs
+++ b/Terminal.Gui/View/Orientation/IOrientation.cs
@@ -1,4 +1,5 @@
-
+#nullable enable
+
 namespace Terminal.Gui;
 using System;
 
diff --git a/Terminal.Gui/View/Orientation/Orientation.cs b/Terminal.Gui/View/Orientation/Orientation.cs
index fa8c7b2b8..480bb435c 100644
--- a/Terminal.Gui/View/Orientation/Orientation.cs
+++ b/Terminal.Gui/View/Orientation/Orientation.cs
@@ -1,4 +1,5 @@
-namespace Terminal.Gui;
+#nullable enable
+namespace Terminal.Gui;
 
 /// <summary>Direction of an element (horizontal or vertical)</summary>
 public enum Orientation
diff --git a/Terminal.Gui/View/Orientation/OrientationHelper.cs b/Terminal.Gui/View/Orientation/OrientationHelper.cs
index 2227494dc..33c33c70f 100644
--- a/Terminal.Gui/View/Orientation/OrientationHelper.cs
+++ b/Terminal.Gui/View/Orientation/OrientationHelper.cs
@@ -1,4 +1,5 @@
-namespace Terminal.Gui;
+#nullable enable
+namespace Terminal.Gui;
 
 /// <summary>
 ///     Helper class for implementing <see cref="IOrientation"/>.
@@ -119,7 +120,7 @@ public class OrientationHelper
     ///         it was not canceled).
     ///     </para>
     /// </remarks>
-    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanging;
+    public event EventHandler<CancelEventArgs<Orientation>>? OrientationChanging;
 
     /// <summary>
     ///     Raised when the orientation has changed.
@@ -134,5 +135,5 @@ public class OrientationHelper
     ///         This event will be raised after the <see cref="IOrientation.OnOrientationChanged"/> method is called.
     ///     </para>
     /// </remarks>
-    public event EventHandler<EventArgs<Orientation>> OrientationChanged;
+    public event EventHandler<EventArgs<Orientation>>? OrientationChanged;
 }
diff --git a/UnitTests/View/Navigation/NavigationTests.cs b/UnitTests/View/Navigation/NavigationTests.cs
index b83fdfad1..2e4b56170 100644
--- a/UnitTests/View/Navigation/NavigationTests.cs
+++ b/UnitTests/View/Navigation/NavigationTests.cs
@@ -1,10 +1,9 @@
 using JetBrains.Annotations;
 using Xunit.Abstractions;
-using static System.Net.Mime.MediaTypeNames;
 
 namespace Terminal.Gui.ViewTests;
 
-public class NavigationTests () : TestsAllViews
+public class NavigationTests (ITestOutputHelper _output) : TestsAllViews
 {
     [Theory]
     [MemberData (nameof (AllViewTypes))]