diff --git a/build.cake b/build.cake
index 24f529ee4a..56653109ae 100644
--- a/build.cake
+++ b/build.cake
@@ -170,6 +170,7 @@ Task("Run-Unit-Tests-Impl")
     RunCoreTest("./tests/Avalonia.Styling.UnitTests", data.Parameters, false);
     RunCoreTest("./tests/Avalonia.Visuals.UnitTests", data.Parameters, false);
     RunCoreTest("./tests/Avalonia.Skia.UnitTests", data.Parameters, false);
+    RunCoreTest("./tests/Avalonia.ReactiveUI.UnitTests", data.Parameters, false);
     if (data.Parameters.IsRunningOnWindows)
     {
         RunCoreTest("./tests/Avalonia.Direct2D1.UnitTests", data.Parameters, false);
diff --git a/samples/VirtualizationDemo/ViewModels/MainWindowViewModel.cs b/samples/VirtualizationDemo/ViewModels/MainWindowViewModel.cs
index eb08ef9656..eba17f92e4 100644
--- a/samples/VirtualizationDemo/ViewModels/MainWindowViewModel.cs
+++ b/samples/VirtualizationDemo/ViewModels/MainWindowViewModel.cs
@@ -7,6 +7,7 @@ using System.Linq;
 using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
+using ReactiveUI.Legacy;
 using ReactiveUI;
 
 namespace VirtualizationDemo.ViewModels
diff --git a/tests/Avalonia.ReactiveUI.UnitTests/Avalonia.ReactiveUI.UnitTests.csproj b/tests/Avalonia.ReactiveUI.UnitTests/Avalonia.ReactiveUI.UnitTests.csproj
index 88f4e08886..7c0ff79183 100644
--- a/tests/Avalonia.ReactiveUI.UnitTests/Avalonia.ReactiveUI.UnitTests.csproj
+++ b/tests/Avalonia.ReactiveUI.UnitTests/Avalonia.ReactiveUI.UnitTests.csproj
@@ -8,6 +8,7 @@
   <Import Project="..\..\build\Rx.props" />
   <Import Project="..\..\build\Microsoft.Reactive.Testing.props" />
   <ItemGroup>
-    <ProjectReference Include="../../src/Avalonia.ReactiveUI/Avalonia.ReactiveUI.csproj"/>
+    <ProjectReference Include="..\Avalonia.UnitTests\Avalonia.UnitTests.csproj" />
+    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj"/>
   </ItemGroup>
 </Project>
diff --git a/tests/Avalonia.ReactiveUI.UnitTests/AvaloniaActivationForViewFetcherTest.cs b/tests/Avalonia.ReactiveUI.UnitTests/AvaloniaActivationForViewFetcherTest.cs
index 694d75f5b7..97701f8437 100644
--- a/tests/Avalonia.ReactiveUI.UnitTests/AvaloniaActivationForViewFetcherTest.cs
+++ b/tests/Avalonia.ReactiveUI.UnitTests/AvaloniaActivationForViewFetcherTest.cs
@@ -4,6 +4,7 @@ using System.Reactive.Disposables;
 using Avalonia.Controls;
 using Avalonia.Rendering;
 using Avalonia.Platform;
+using Avalonia.UnitTests;
 using Avalonia;
 using ReactiveUI;
 using DynamicData;
@@ -16,23 +17,6 @@ namespace Avalonia
     {
         public class TestUserControl : UserControl, IActivatable { }
 
-        public class FakeRenderDecorator : Decorator, IRenderRoot
-        {
-            public Size ClientSize => new Size(100, 100);
-
-            public IRenderer Renderer { get; }
-
-            public double RenderScaling => 1;
-
-            public IRenderTarget CreateRenderTarget() => null;
-
-            public void Invalidate(Rect rect) { }
-
-            public Point PointToClient(Point point) => point;
-
-            public Point PointToScreen(Point point) => point;
-        }
-
         public class TestUserControlWithWhenActivated : UserControl, IActivatable
         {
             public bool Active { get; private set; }
@@ -60,7 +44,7 @@ namespace Avalonia
                 .Bind(out var activated)
                 .Subscribe();
 
-            var fakeRenderedDecorator = new FakeRenderDecorator();
+            var fakeRenderedDecorator = new TestRoot();
             fakeRenderedDecorator.Child = userControl;
             Assert.True(activated[0]);
             Assert.Equal(1, activated.Count);
@@ -94,7 +78,7 @@ namespace Avalonia
             var userControl = new TestUserControlWithWhenActivated();
             Assert.False(userControl.Active);
 
-            var fakeRenderedDecorator = new FakeRenderDecorator();
+            var fakeRenderedDecorator = new TestRoot();
             fakeRenderedDecorator.Child = userControl;
             Assert.True(userControl.Active);