diff --git a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs
index 05339c43b0..e9cb2bf450 100644
--- a/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs
+++ b/tests/Avalonia.Base.UnitTests/AvaloniaObjectTests_Direct.cs
@@ -187,7 +187,7 @@ namespace Avalonia.Base.UnitTests
 
             source.OnNext(45);
 
-            Assert.Equal(null, target.Foo);
+            Assert.Null(target.Foo);
         }
 
         [Fact]
diff --git a/tests/Avalonia.Controls.UnitTests/Generators/ItemContainerGeneratorTests.cs b/tests/Avalonia.Controls.UnitTests/Generators/ItemContainerGeneratorTests.cs
index 01b550fb3b..9b4be59647 100644
--- a/tests/Avalonia.Controls.UnitTests/Generators/ItemContainerGeneratorTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Generators/ItemContainerGeneratorTests.cs
@@ -66,7 +66,7 @@ namespace Avalonia.Controls.UnitTests.Generators
             target.Dematerialize(1, 1);
 
             Assert.Equal(containers[0].ContainerControl, target.ContainerFromIndex(0));
-            Assert.Equal(null, target.ContainerFromIndex(1));
+            Assert.Null(target.ContainerFromIndex(1));
             Assert.Equal(containers[2].ContainerControl, target.ContainerFromIndex(2));
         }
 
diff --git a/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_InTemplate.cs b/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_InTemplate.cs
index e32c703409..a524ca3e89 100644
--- a/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_InTemplate.cs
+++ b/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_InTemplate.cs
@@ -107,7 +107,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             target.Content = child;
             target.Content = null;
 
-            Assert.Equal(null, child.GetLogicalParent());
+            Assert.Null(child.GetLogicalParent());
             Assert.Empty(target.GetLogicalChildren());
         }
 
@@ -120,7 +120,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             target.Content = child;
             target.Content = null;
 
-            Assert.Equal(null, child.GetVisualParent());
+            Assert.Null(child.GetVisualParent());
             Assert.Empty(target.GetVisualChildren());
         }
 
diff --git a/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_Standalone.cs b/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_Standalone.cs
index 589b1d67d2..032928d673 100644
--- a/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_Standalone.cs
+++ b/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_Standalone.cs
@@ -191,7 +191,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             target.Content = "bar";
             target.UpdateChild();
 
-            Assert.Equal(null, foo.Parent);
+            Assert.Null(foo.Parent);
 
             logicalChildren = target.GetLogicalChildren();
 
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
index 7ee9fbbf52..a60074fa43 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
@@ -171,7 +171,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             target.SelectedItem = new Item();
 
-            Assert.Equal(null, target.SelectedItem);
+            Assert.Null(target.SelectedItem);
             Assert.Equal(-1, target.SelectedIndex);
         }
 
@@ -278,7 +278,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             target.Items = null;
 
-            Assert.Equal(null, target.SelectedItem);
+            Assert.Null(target.SelectedItem);
             Assert.Equal(-1, target.SelectedIndex);
         }
 
@@ -305,7 +305,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             items.RemoveAt(1);
 
-            Assert.Equal(null, target.SelectedItem);
+            Assert.Null(target.SelectedItem);
             Assert.Equal(-1, target.SelectedIndex);
         }
 
@@ -334,7 +334,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             items.Clear();
 
-            Assert.Equal(null, target.SelectedItem);
+            Assert.Null(target.SelectedItem);
             Assert.Equal(-1, target.SelectedIndex);
         }
 
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs
index d8600f472d..642f594e4d 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs
@@ -76,7 +76,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             target.SelectedItems = new AvaloniaList<object>();
 
             Assert.Equal(-1, target.SelectedIndex);
-            Assert.Equal(null, target.SelectedItem);
+            Assert.Null(target.SelectedItem);
         }
 
         [Fact]
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests_RelativeSource.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests_RelativeSource.cs
index e912770470..c46fb6fce2 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests_RelativeSource.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests_RelativeSource.cs
@@ -117,7 +117,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Data
             };
 
             target.Bind(TextBox.TextProperty, binding);
-            Assert.Equal(null, target.Text);
+            Assert.Null(target.Text);
         }
 
         [Fact]
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs
index 49a88e8fae..aa1e56f2a5 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Templates/MemberSelectorTests.cs
@@ -63,7 +63,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Templates
         {
             var selector = new MemberSelector() { MemberName = "StringValue" };
 
-            Assert.Equal(null, selector.Select(null));
+            Assert.Null(selector.Select(null));
         }
 
         [Fact]
@@ -73,7 +73,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Templates
 
             var data = new Item() { StringValue = "Value1" };
 
-            Assert.Same(null, selector.Select(data));
+            Assert.Null(selector.Select(data));
         }
 
         [Fact]