ChrisPulman · Sep 29, 2026 · Sep 27, 2026 · Sep 27, 2026 · Sep 29, 2026 · Sep 29, 2026
diff --git a/Directory.Packages.props b/Directory.Packages.props
@@ -7,22 +7,22 @@
     <Net10PackageVersion>10.0.12</Net10PackageVersion>
     <Net11PreviewPackageVersion>11.0.0-rc.1.26425.128</Net11PreviewPackageVersion>
     <MauiNet9PackageVersion>9.0.120</MauiNet9PackageVersion>
-    <MauiNet10PackageVersion>10.0.101</MauiNet10PackageVersion>
+    <MauiNet10PackageVersion>10.0.110</MauiNet10PackageVersion>
     <MauiNet11PackageVersion>11.0.0-rc.1.26451.6</MauiNet11PackageVersion>
-    <ReactiveUIPackageVersion>24.2.0</ReactiveUIPackageVersion>
+    <ReactiveUIPackageVersion>25.1.1</ReactiveUIPackageVersion>
     <RoslynAnalysersVersion>5.1.2</RoslynAnalysersVersion>
-    <PrimitivesVersion>8.0.0</PrimitivesVersion>
+    <PrimitivesVersion>8.4.0</PrimitivesVersion>
+    <Net10BuildToolsVersion>18.9.6</Net10BuildToolsVersion>
+    <Net11BuildToolsVersion>18.10.1</Net11BuildToolsVersion>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageVersion Include="Avalonia" Version="12.1.2" />
-    <PackageVersion Include="Avalonia.Desktop" Version="12.1.2" />
-    <PackageVersion Include="Avalonia.Themes.Fluent" Version="12.1.2" />
+    <PackageVersion Include="Avalonia" Version="12.1.3" />
+    <PackageVersion Include="Avalonia.Desktop" Version="12.1.3" />
+    <PackageVersion Include="Avalonia.Themes.Fluent" Version="12.1.3" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.15.8" />
     <PackageVersion Include="CP.Nuke.BuildTools" Version="3.0.2" />
     <PackageVersion Include="log4net" Version="3.4.0" />
-    <PackageVersion Include="Microsoft.Build.Tasks.Core" Version="18.9.6" />
-    <PackageVersion Include="Microsoft.Build.Utilities.Core" Version="18.10.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.10.1" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="10.0.401" />
     <PackageVersion Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.11.2" />
@@ -35,7 +35,7 @@
     <!--Reactive UI with ReactiveUI.Primitives support-->
     <PackageVersion Include="ReactiveUI.Primitives" Version="$(PrimitivesVersion)" />
     <PackageVersion Include="ReactiveUI" Version="$(ReactiveUIPackageVersion)" />
-    <PackageVersion Include="ReactiveUI.Avalonia" Version="12.1.2" />
+    <PackageVersion Include="ReactiveUI.Avalonia" Version="12.1.5" />
     <PackageVersion Include="ReactiveUI.Core" Version="$(ReactiveUIPackageVersion)" />
     <PackageVersion Include="ReactiveUI.Disposables" Version="$(PrimitivesVersion)" />
     <PackageVersion Include="ReactiveUI.Drawing" Version="$(ReactiveUIPackageVersion)" />
@@ -46,7 +46,7 @@
     <PackageVersion Include="ReactiveUI.Reactive" Version="$(ReactiveUIPackageVersion)" />
     <!--Reactive UI with System.Reactive support-->
     <PackageVersion Include="ReactiveUI.Primitives.Reactive" Version="$(PrimitivesVersion)" />
-    <PackageVersion Include="ReactiveUI.Avalonia.Reactive" Version="12.1.2" />
+    <PackageVersion Include="ReactiveUI.Avalonia.Reactive" Version="12.1.5" />
     <PackageVersion Include="ReactiveUI.Drawing.Reactive" Version="$(ReactiveUIPackageVersion)" />
     <PackageVersion Include="ReactiveUI.Maui.Reactive" Version="$(ReactiveUIPackageVersion)" />
     <PackageVersion Include="ReactiveUI.WinForms.Reactive" Version="$(ReactiveUIPackageVersion)" />
@@ -55,16 +55,17 @@
     <PackageVersion Include="Roslynator.Analyzers" Version="5.0.0" />
     <PackageVersion Include="Splat" Version="21.0.0" />
     <PackageVersion Include="Splat.Microsoft.Extensions.DependencyInjection" Version="21.0.0" />
-    <PackageVersion Include="SQLitePCLRaw.lib.e_sqlite3" Version="3.50.3" />
     <PackageVersion Include="StyleSharp.Analyzers" Version="$(RoslynAnalysersVersion)" />
     <PackageVersion Include="PerformanceSharp.Analyzers" Version="$(RoslynAnalysersVersion)" />
     <PackageVersion Include="SecuritySharp.Analyzers" Version="$(RoslynAnalysersVersion)" />
     <PackageVersion Include="Tmds.DBus.Protocol" Version="0.95.1" />
-    <PackageVersion Include="TUnit" Version="1.68.17" />
-    <PackageVersion Include="Verify.TUnit" Version="32.0.1" />
+    <PackageVersion Include="TUnit" Version="1.72.0" />
+    <PackageVersion Include="SQLitePCLRaw.lib.e_sqlite3" Version="3.53.3" />
   </ItemGroup>
 
   <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net11.0')) != 'true'">
+    <PackageVersion Include="Microsoft.Build.Tasks.Core" Version="$(Net10BuildToolsVersion)" />
+    <PackageVersion Include="Microsoft.Build.Utilities.Core" Version="$(Net10BuildToolsVersion)" />
     <PackageVersion Include="Microsoft.Extensions.Configuration.Json" Version="$(Net10PackageVersion)" />
     <PackageVersion Include="Microsoft.Extensions.FileSystemGlobbing" Version="$(Net10PackageVersion)" />
     <PackageVersion Include="Microsoft.Extensions.Hosting" Version="$(Net10PackageVersion)" />
@@ -77,6 +78,8 @@
   </ItemGroup>
 
   <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net11.0')) == 'true'">
+    <PackageVersion Include="Microsoft.Build.Tasks.Core" Version="$(Net11BuildToolsVersion)" />
+    <PackageVersion Include="Microsoft.Build.Utilities.Core" Version="$(Net11BuildToolsVersion)" />
     <PackageVersion Include="Microsoft.Extensions.Configuration.Json" Version="$(Net11PreviewPackageVersion)" />
     <PackageVersion Include="Microsoft.Extensions.FileSystemGlobbing" Version="$(Net11PreviewPackageVersion)" />
     <PackageVersion Include="Microsoft.Extensions.Hosting" Version="$(Net11PreviewPackageVersion)" />

diff --git a/src/Directory.Build.props b/src/Directory.Build.props
@@ -70,7 +70,6 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk"/>
     <PackageReference Include="Microsoft.Testing.Extensions.CodeCoverage"/>
     <PackageReference Include="PublicApiGenerator"/>
-    <PackageReference Include="Verify.TUnit"/>
 
     <None Include="$(MSBuildThisFileDirectory)testconfig.json">
       <Link>$(AssemblyName).testconfig.json</Link>

diff --git a/src/Extensions.Hosting.ReactiveUI.WinForms/HostBuilderReactiveUiExtensions.cs b/src/Extensions.Hosting.ReactiveUI.WinForms/HostBuilderReactiveUiExtensions.cs
@@ -2,7 +2,10 @@
 // ReactiveUI Association Incorporated licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
+using ReactiveMarbles.Extensions.Hosting.WinForms;
 #if REACTIVE_SHIM
 using ReactiveUI.Reactive.Builder;
 #else
@@ -61,9 +64,15 @@ public IHostApplicationBuilder ConfigureSplatForMicrosoftDependencyResolver()
             _ = hostBuilder ?? throw new ArgumentNullException(nameof(hostBuilder));
 
             hostBuilder.Services.UseMicrosoftDependencyResolver();
+            hostBuilder.Services.TryAddEnumerable(
+                ServiceDescriptor.Singleton<IWinFormsService>(new ReactiveUiWinFormsService()));
             var reactiveUiBuilder = AppLocator.CurrentMutable.CreateReactiveUIBuilder()
                 .WithRegistration(static r => r.InitializeSplat())
-                .WithWinForms();
+#if REACTIVE_SHIM
+                .WithPlatformModule<global::ReactiveUI.Reactive.Winforms.Registrations>();
+#else
+                .WithPlatformModule<global::ReactiveUI.Winforms.Registrations>();
+#endif
             _ = reactiveUiBuilder.BuildApp();
             return hostBuilder;
         }
@@ -82,9 +91,15 @@ public IHostBuilder ConfigureSplatForMicrosoftDependencyResolver() =>
             hostBuilder.ConfigureServices(static (serviceCollection) =>
             {
                 serviceCollection.UseMicrosoftDependencyResolver();
+                serviceCollection.TryAddEnumerable(
+                    ServiceDescriptor.Singleton<IWinFormsService>(new ReactiveUiWinFormsService()));
                 var reactiveUiBuilder = AppLocator.CurrentMutable.CreateReactiveUIBuilder()
                     .WithRegistration(static r => r.InitializeSplat())
-                    .WithWinForms();
+#if REACTIVE_SHIM
+                    .WithPlatformModule<global::ReactiveUI.Reactive.Winforms.Registrations>();
+#else
+                    .WithPlatformModule<global::ReactiveUI.Winforms.Registrations>();
+#endif
                 _ = reactiveUiBuilder.BuildApp();
             });
     }

diff --git a/src/Extensions.Hosting.ReactiveUI.WinForms/ReactiveUiWinFormsService.cs b/src/Extensions.Hosting.ReactiveUI.WinForms/ReactiveUiWinFormsService.cs
@@ -0,0 +1,25 @@
+// Copyright (c) 2019-2026 ReactiveUI Association Incorporated. All rights reserved.
+// ReactiveUI Association Incorporated licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using ReactiveMarbles.Extensions.Hosting.WinForms;
+#if REACTIVE_SHIM
+using ControlSequencer = ReactiveUI.Primitives.Reactive.Concurrency.ControlSequencer;
+using RxSchedulers = ReactiveUI.Reactive.RxSchedulers;
+#else
+using ControlSequencer = ReactiveUI.Primitives.Concurrency.ControlSequencer;
+using RxSchedulers = ReactiveUI.RxSchedulers;
+#endif
+
+#if REACTIVE_SHIM
+namespace ReactiveMarbles.Extensions.Hosting.Reactive.ReactiveUI;
+#else
+namespace ReactiveMarbles.Extensions.Hosting.ReactiveUI;
+#endif
+
+/// <summary>Initializes ReactiveUI on the hosted Windows Forms UI thread.</summary>
+internal sealed class ReactiveUiWinFormsService : IWinFormsService
+{
+    /// <inheritdoc />
+    public void Initialize() => RxSchedulers.MainThreadScheduler = ControlSequencer.Main;
+}
diff --git a/src/Extensions.Hosting.ReactiveUI.WinUI/HostBuilderReactiveUiExtensions.cs b/src/Extensions.Hosting.ReactiveUI.WinUI/HostBuilderReactiveUiExtensions.cs
@@ -3,10 +3,11 @@
 // See the LICENSE file in the project root for full license information.
 
 using Microsoft.Extensions.Hosting;
-using ReactiveUI.Builder;
 
 #if REACTIVE_SHIM
 using ReactiveUI.Reactive.Builder;
+#else
+using ReactiveUI.Builder;
 #endif
 using Splat;
 using Splat.Microsoft.Extensions.DependencyInjection;

diff --git a/src/Extensions.Hosting.ReactiveUI.Wpf/HostBuilderReactiveUiExtensions.cs b/src/Extensions.Hosting.ReactiveUI.Wpf/HostBuilderReactiveUiExtensions.cs
@@ -39,7 +39,12 @@ private static void ConfigureReactiveUi(IServiceCollection services)
             ServiceDescriptor.Singleton<IWpfService>(new ReactiveUiWpfSchedulerService()));
         var reactiveUiBuilder = AppLocator.CurrentMutable.CreateReactiveUIBuilder()
             .WithRegistration(static r => r.InitializeSplat())
-            .WithWpf();
+#if REACTIVE_SHIM
+            .WithPlatformModule<global::ReactiveUI.Reactive.Wpf.Registrations>()
+#else
+            .WithPlatformModule<global::ReactiveUI.Wpf.Registrations>()
+#endif
+            .WithWpfConverters();
         _ = reactiveUiBuilder.BuildApp();
     }
 

diff --git a/src/examples/Extensions.Hosting.ReactiveAvalonia.Example/AppViewModel.cs b/src/examples/Extensions.Hosting.ReactiveAvalonia.Example/AppViewModel.cs
@@ -98,7 +98,7 @@ private ObservableAsPropertyHelper<IEnumerable<NugetDetailsViewModel>> EnsureSea
             .Where(static term => !string.IsNullOrWhiteSpace(term))
             .SelectMany(term => Signal.FromAsync(token => SearchNuGetPackages(term, token)))
             .ObserveOn(RxSchedulers.MainThreadScheduler)
-            .ToProperty(this, x => x.SearchResults);
+            .ToProperty(this, static x => x.SearchResults);
         _ = _searchResults.ThrownExceptions.Subscribe(static error => { });
         return _searchResults;
     }
@@ -116,7 +116,7 @@ private ObservableAsPropertyHelper<bool> EnsureAvailabilityInitialized()
         _isAvailable = this
             .WhenAnyValue(x => x.SearchResults)
             .Select(static searchResults => searchResults is not null)
-            .ToProperty(this, x => x.IsAvailable);
+            .ToProperty(this, static x => x.IsAvailable);
         return _isAvailable;
     }
 }
diff --git a/src/examples/Extensions.Hosting.ReactiveAvalonia.Example/Program.cs b/src/examples/Extensions.Hosting.ReactiveAvalonia.Example/Program.cs
@@ -9,7 +9,6 @@
 using ReactiveMarbles.Extensions.Hosting.AppServices;
 using ReactiveMarbles.Extensions.Hosting.Avalonia;
 using ReactiveMarbles.Extensions.Hosting.ReactiveUI;
-using ReactiveUI;
 
 namespace Extensions.Hosting.ReactiveAvalonia.Example;
 

diff --git a/src/examples/Extensions.Hosting.ReactiveWpf.Example/App.xaml.cs b/src/examples/Extensions.Hosting.ReactiveWpf.Example/App.xaml.cs
@@ -9,7 +9,6 @@
 using ReactiveMarbles.Extensions.Hosting.AppServices;
 using ReactiveMarbles.Extensions.Hosting.ReactiveUI;
 using ReactiveMarbles.Extensions.Hosting.Wpf;
-using ReactiveUI;
 
 namespace Extensions.Hosting.Reactive.Example;
 

diff --git a/src/examples/Extensions.Hosting.ReactiveWpf.Example/AppViewModel.cs b/src/examples/Extensions.Hosting.ReactiveWpf.Example/AppViewModel.cs
@@ -109,7 +109,7 @@ private ObservableAsPropertyHelper<IEnumerable<NugetDetailsViewModel>> EnsureSea
             .Where(static term => !string.IsNullOrWhiteSpace(term))
             .SelectMany(term => Signal.FromAsync(token => SearchNuGetPackages(term, token)))
             .ObserveOn(RxSchedulers.MainThreadScheduler)
-            .ToProperty(this, x => x.SearchResults);
+            .ToProperty(this, static x => x.SearchResults);
         _ = _searchResults.ThrownExceptions.Subscribe(static error => { /* Handle errors here */ });
         return _searchResults;
     }
@@ -127,7 +127,7 @@ private ObservableAsPropertyHelper<bool> EnsureAvailabilityInitialized()
         _isAvailable = this
             .WhenAnyValue(x => x.SearchResults)
             .Select(static searchResults => searchResults is not null)
-            .ToProperty(this, x => x.IsAvailable);
+            .ToProperty(this, static x => x.IsAvailable);
         return _isAvailable;
     }
 }
diff --git a/src/tests/Extensions.Hosting.WinForms.Tests/ReactiveUiWinFormsExtensionsTests.cs b/src/tests/Extensions.Hosting.WinForms.Tests/ReactiveUiWinFormsExtensionsTests.cs
@@ -2,11 +2,17 @@
 // ReactiveUI Association Incorporated licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using ReactiveMarbles.Extensions.Hosting.WinForms;
 #if REACTIVE_SHIM
 using ReactiveMarbles.Extensions.Hosting.Reactive.ReactiveUI;
+using ControlSequencer = ReactiveUI.Primitives.Reactive.Concurrency.ControlSequencer;
+using RxSchedulers = ReactiveUI.Reactive.RxSchedulers;
 #else
 using ReactiveMarbles.Extensions.Hosting.ReactiveUI;
+using ControlSequencer = ReactiveUI.Primitives.Concurrency.ControlSequencer;
+using RxSchedulers = ReactiveUI.RxSchedulers;
 #endif
 
 namespace Extensions.Hosting.WinForms.Tests;
@@ -15,6 +21,36 @@ namespace Extensions.Hosting.WinForms.Tests;
 [NotInParallel]
 public sealed class ReactiveUiWinFormsExtensionsTests
 {
+    /// <summary>Gets the maximum duration allowed for hosted UI startup and shutdown.</summary>
+    private static readonly TimeSpan Timeout = TimeSpan.FromSeconds(10);
+
+    /// <summary>Verifies scheduler binding on the hosted UI thread before its message loop starts.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
+    [Test]
+    public async Task ConfigureSplatForMicrosoftDependencyResolver_HostedUiBindsWinFormsScheduler()
+    {
+        var originalScheduler = RxSchedulers.MainThreadScheduler;
+        var captureService = new SchedulerCaptureService();
+        var hostBuilder = Host.CreateApplicationBuilder();
+        _ = hostBuilder.ConfigureSplatForMicrosoftDependencyResolver();
+        _ = hostBuilder.ConfigureWinForms(static context => context.EnableVisualStyles = false);
+        _ = hostBuilder.Services.AddSingleton<IWinFormsService>(captureService);
+        using var host = hostBuilder.Build();
+
+        try
+        {
+            await host.StartAsync().WaitAsync(Timeout);
+            var schedulerIsBound = await captureService.SchedulerIsBound.Task.WaitAsync(Timeout);
+
+            await Assert.That(schedulerIsBound).IsTrue();
+        }
+        finally
+        {
+            await host.StopAsync().WaitAsync(Timeout);
+            RxSchedulers.MainThreadScheduler = originalScheduler;
+        }
+    }
+
     /// <summary>Verifies that application builders reject a null receiver.</summary>
     /// <returns>A task that represents the asynchronous test operation.</returns>
     [Test]
@@ -82,4 +118,14 @@ public async Task MapSplatLocator_NullHost_ReturnsNullAndInvokesFactoryWithNull(
         await Assert.That(mappedHost).IsNull();
         await Assert.That(mappedProvider).IsNull();
     }
+
+    /// <summary>Captures the scheduler after the ReactiveUI service initializes on the UI thread.</summary>
+    private sealed class SchedulerCaptureService : IWinFormsService
+    {
+        /// <summary>Gets the scheduler binding result.</summary>
+        public TaskCompletionSource<bool> SchedulerIsBound { get; } = new(TaskCreationOptions.RunContinuationsAsynchronously);
+
+        /// <inheritdoc />
+        public void Initialize() => SchedulerIsBound.SetResult(RxSchedulers.MainThreadScheduler is ControlSequencer);
+    }
 }