diff --git a/src/Consolonia.Core/Infrastructure/ArrowsAndKeyboardNavigationHandler.cs b/src/Consolonia.Core/Infrastructure/ArrowsAndKeyboardNavigationHandler.cs
index 6f999e99..4fc52088 100644
--- a/src/Consolonia.Core/Infrastructure/ArrowsAndKeyboardNavigationHandler.cs
+++ b/src/Consolonia.Core/Infrastructure/ArrowsAndKeyboardNavigationHandler.cs
@@ -37,11 +37,11 @@ NavigationDirection.Down or
                 NavigationDirection.Up)
             {
                 var elementCast = (InputElement)element;
-                var visualRoot = (Visual)elementCast.GetVisualRoot()!;
+                var visualRoot = (Visual)elementCast.GetVisualRoot();
                 (Point p1, Point p2) = GetOriginalPoint(elementCast.GetTransformedBounds().NotNull().Clip);
                 Point originalPoint = p1 / 2 + p2 / 2;
 
-                var focusableElements = visualRoot.GetVisualDescendants()
+                var focusableElements = visualRoot!.GetVisualDescendants()
                     .OfType<InputElement>()
                     // only focusable
                     .Where(inputElement => inputElement.Focusable && inputElement.IsEffectivelyEnabled &&
diff --git a/src/Consolonia.Themes.TurboVision/Templates/Controls/Dialog/DialogWindow.cs b/src/Consolonia.Themes.TurboVision/Templates/Controls/Dialog/DialogWindow.cs
index 47b2cc90..f3081bd1 100644
--- a/src/Consolonia.Themes.TurboVision/Templates/Controls/Dialog/DialogWindow.cs
+++ b/src/Consolonia.Themes.TurboVision/Templates/Controls/Dialog/DialogWindow.cs
@@ -107,10 +107,10 @@ public Task ShowDialogAsync(Control parent)
             return _taskCompletionSource.Task;
         }
 
-        private static DialogHost GetDialogHost(Control parent)
+        private static DialogHost GetDialogHost(Visual parent)
         {
-            var window = parent.FindAncestorOfType<Window>(true)!;
-            DialogHost dialogHost = window.GetValue(DialogHost.DialogHostProperty);
+            var window = parent.FindAncestorOfType<Window>(true);
+            DialogHost dialogHost = window!.GetValue(DialogHost.DialogHostProperty);
             return dialogHost;
         }
 
diff --git a/src/Consolonia.Themes.TurboVision/Templates/Controls/DialogWrap.axaml.cs b/src/Consolonia.Themes.TurboVision/Templates/Controls/DialogWrap.axaml.cs
index 697d7769..9f4b1be5 100644
--- a/src/Consolonia.Themes.TurboVision/Templates/Controls/DialogWrap.axaml.cs
+++ b/src/Consolonia.Themes.TurboVision/Templates/Controls/DialogWrap.axaml.cs
@@ -11,7 +11,8 @@
 
 namespace Consolonia.Themes.TurboVision.Templates.Controls
 {
-    [SuppressMessage("Resharper", "PartialTypeWithSinglePart")]
+    [SuppressMessage("Usage", "PartialTypeWithSinglePart", Justification = "Partial class required for XAML code generation.")]
+    // ReSharper disable once PartialTypeWithSinglePart
     internal partial class DialogWrap : UserControl
     {
         public readonly ContentPresenter FoundContentPresenter;
@@ -24,15 +25,15 @@ public DialogWrap()
             
             AttachedToVisualTree += (_, _) =>
             {
-                var parentWindow = this.FindAncestorOfType<Window>()!;
-                _disposable = parentWindow.GetPropertyChangedObservable(TopLevel.ClientSizeProperty).Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs>(
+                var parentWindow = this.FindAncestorOfType<Window>();
+                _disposable = parentWindow!.GetPropertyChangedObservable(TopLevel.ClientSizeProperty).Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs>(
                     args =>
                     {
                         var newSize = (Size)args.NewValue!;
 
                         SetNewSize(newSize);
                     }));
-                SetNewSize(parentWindow.ClientSize);
+                SetNewSize(parentWindow!.ClientSize);
             };
             DetachedFromLogicalTree += (_, _) => { _disposable.Dispose(); };
         }
diff --git a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ComboBoxExtensions.cs b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ComboBoxExtensions.cs
index b6f56484..030e058d 100644
--- a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ComboBoxExtensions.cs
+++ b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ComboBoxExtensions.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Reflection;
 using Avalonia;
 using Avalonia.Controls;
diff --git a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ConsoloniaTextPresenter.cs b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ConsoloniaTextPresenter.cs
index 9b159310..6e0c0d36 100644
--- a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ConsoloniaTextPresenter.cs
+++ b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/ConsoloniaTextPresenter.cs
@@ -69,11 +69,11 @@ static ConsoloniaTextPresenter()
         public ConsoloniaTextPresenter()
         {
             // we need to disable blinking caret, our terminal caret blinks itself once shown
-            var caretTickTimer = (DispatcherTimer)TickTimerField.GetValue(this)!;
-            caretTickTimer.Interval =
+            var caretTickTimer = (DispatcherTimer)TickTimerField.GetValue(this);
+            caretTickTimer!.Interval =
                 TimeSpan.FromMilliseconds(int
                     .MaxValue); //see DispatcherTimer.Interval, since we can not disable it, setting it to the longest interval possible
-            caretTickTimer.Tick += (_, _) => throw new NotImplementedException("How to disable timer completely?");
+            caretTickTimer!.Tick += (_, _) => throw new NotImplementedException("How to disable timer completely?");
 
             CaretBrush =
                 new FourBitColorBrush(ConsoleColor.Black, PixelBackgroundMode.Transparent); // we want to draw own caret
diff --git a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/DropDownExtensions.cs b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/DropDownExtensions.cs
index fa44349e..6a8594a2 100644
--- a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/DropDownExtensions.cs
+++ b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/DropDownExtensions.cs
@@ -19,28 +19,28 @@ public static void ProcessFocusOnOpen<TElementType, TParentControl>(AvaloniaProp
             where TElementType : Control where TParentControl : Control
         {
             var dropDownControl = (TElementType)args.Sender;
-            var parentControl = dropDownControl.FindLogicalAncestorOfType<TParentControl>()!;
+            var parentControl = dropDownControl.FindLogicalAncestorOfType<TParentControl>();
 
             if (args.NewValue.Value)
             {
                 dropDownControl.AttachedToVisualTree += focusDropDownAction;
 
-                IDisposable disposable1 = parentControl.GetPropertyChangedObservable(InputElement.IsFocusedProperty)
+                IDisposable disposable1 = parentControl!.GetPropertyChangedObservable(InputElement.IsFocusedProperty)
                     .Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs>(eventArgs =>
                     {
                         if (!(bool)eventArgs.NewValue! && !dropDownControl.IsKeyboardFocusWithin)
-                            Dispatcher.UIThread.Post(() => { parentControl.SetValue(dropDownProperty, false); });
+                            Dispatcher.UIThread.Post(() => { parentControl!.SetValue(dropDownProperty, false); });
                     }));
 
                 IDisposable disposable2 = dropDownControl
                     .GetPropertyChangedObservable(InputElement.IsKeyboardFocusWithinProperty)
                     .Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs>(eventArgs =>
                     {
-                        if (!(bool)eventArgs.NewValue! && !parentControl.IsKeyboardFocusWithin)
+                        if (!(bool)eventArgs.NewValue! && !parentControl!.IsKeyboardFocusWithin)
                             Dispatcher.UIThread.Post(() =>
                             {
-                                parentControl.SetValue(dropDownProperty, false);
-                                focusParentAction(parentControl);
+                                parentControl!.SetValue(dropDownProperty, false);
+                                focusParentAction(parentControl!);
                             });
                     }));
 
diff --git a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/MenuExtensions.cs b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/MenuExtensions.cs
index 36b3149f..b7904c56 100644
--- a/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/MenuExtensions.cs
+++ b/src/Consolonia.Themes.TurboVision/Templates/Controls/Helpers/MenuExtensions.cs
@@ -35,10 +35,10 @@ static MenuExtensions()
                             if (!(bool)eventArgs.NewValue!)
                                 Dispatcher.UIThread.Post(() =>
                                 {
-                                    var focusedControl = (Control)AvaloniaLocator.Current.GetRequiredService<IFocusManager>()!.GetFocusedElement()!;
+                                    var focusedControl = (Control)AvaloniaLocator.Current.GetRequiredService<IFocusManager>()!.GetFocusedElement();
                                     var menuItems = visual.GetLogicalAncestors().OfType<MenuItem>();
 
-                                    var focusedTree = focusedControl.GetLogicalAncestors();
+                                    var focusedTree = focusedControl!.GetLogicalAncestors();
 
                                     foreach (MenuItem menuItem in menuItems.Where(item => !focusedTree.Contains(item))
                                                  .ToArray())