diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/StaticResourceExtensionTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/StaticResourceExtensionTests.cs
index 0ee7384c7d..fb3fd6d7d4 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/StaticResourceExtensionTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/StaticResourceExtensionTests.cs
@@ -29,7 +29,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -72,7 +72,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -119,7 +119,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -149,7 +149,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -200,7 +200,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");
-                var brush = (SolidColorBrush)button.Background;
+                var brush = (ISolidColorBrush)button.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -229,7 +229,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");
-                var brush = (SolidColorBrush)button.Background;
+                var brush = (ISolidColorBrush)button.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -263,7 +263,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var border = window.FindControl<Border>("border");
-                var brush = (SolidColorBrush)border.Background;
+                var brush = (ISolidColorBrush)border.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -344,7 +344,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
                 window.Show();
 
                 var border = (Border)button.GetVisualChildren().Single();
-                var brush = (SolidColorBrush)border.Background;
+                var brush = (ISolidColorBrush)border.Background;
                 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -484,12 +484,12 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
 
             userControl.Content = null;
 
-            brush = (SolidColorBrush)border.Background;
+            brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }