diff --git a/MediatR.sln b/MediatR.sln
index 59e42981..fe11e313 100644
--- a/MediatR.sln
+++ b/MediatR.sln
@@ -21,6 +21,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		Push.ps1 = Push.ps1
 		README.md = README.md
 		.github\workflows\release.yml = .github\workflows\release.yml
+		MediatR.snk = MediatR.snk
 	EndProjectSection
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MediatR.Benchmarks", "test\MediatR.Benchmarks\MediatR.Benchmarks.csproj", "{1FA62162-F8F1-4CAD-B08E-8DCA603395AD}"
diff --git a/src/MediatR/MediatR.csproj b/src/MediatR/MediatR.csproj
index 2f5a48a4..ef9af93f 100644
--- a/src/MediatR/MediatR.csproj
+++ b/src/MediatR/MediatR.csproj
@@ -30,6 +30,12 @@
     <None Include="..\..\LICENSE.md" Pack="true" PackagePath=""/>
     <None Include="..\..\README.md" Pack="true" PackagePath="\" />
   </ItemGroup>
+  
+  <ItemGroup>
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleToAttribute">
+      <_Parameter1>MediatR.Tests, PublicKey=002400000480000094000000060200000024000052534131000400000100010091986edd141861f402457659cb82b56cf6a0d60b3bd2e5aa4ea73d88afa929d278462d6c4c0e2ecbce21948c15514a310a82e6b2e6beaab6cb14230a03bc026609be59f938423f2490fa0033ae87a982fb4950db77d1a4635e14f7727161e93e5511de766ed8e515efd801464b7820a27fca30a32161485824e442cc5ffecfbe</_Parameter1>
+    </AssemblyAttribute>
+  </ItemGroup>
 
   <ItemGroup>
     <PackageReference Include="IsExternalInit" Version="1.0.3">
diff --git a/src/MediatR/MicrosoftExtensionsDI/ServiceCollectionExtensions.cs b/src/MediatR/MicrosoftExtensionsDI/MediatRServiceCollectionExtensions.cs
similarity index 85%
rename from src/MediatR/MicrosoftExtensionsDI/ServiceCollectionExtensions.cs
rename to src/MediatR/MicrosoftExtensionsDI/MediatRServiceCollectionExtensions.cs
index 3b7b31a1..c6982473 100644
--- a/src/MediatR/MicrosoftExtensionsDI/ServiceCollectionExtensions.cs
+++ b/src/MediatR/MicrosoftExtensionsDI/MediatRServiceCollectionExtensions.cs
@@ -18,7 +18,7 @@ namespace Microsoft.Extensions.DependencyInjection;
 /// This does not scan for any <see cref="IPipelineBehavior{TRequest,TResponse}"/> instances including <see cref="RequestPreProcessorBehavior{TRequest,TResponse}"/> and <see cref="RequestPreProcessorBehavior{TRequest,TResponse}"/>.
 /// To register behaviors, use the <see cref="ServiceCollectionServiceExtensions.AddTransient(IServiceCollection,Type,Type)"/> with the open generic or closed generic types.
 /// </summary>
-public static class ServiceCollectionExtensions
+public static class MediatRServiceCollectionExtensions
 {
     /// <summary>
     /// Registers handlers and mediator types from the specified assemblies
@@ -63,8 +63,13 @@ internal static void CheckLicense(this IServiceProvider serviceProvider)
     {
         if (LicenseChecked == false)
         {
-            var licenseAccessor = serviceProvider.GetRequiredService<LicenseAccessor>();
-            var licenseValidator = serviceProvider.GetRequiredService<LicenseValidator>();
+            var licenseAccessor = serviceProvider.GetService<LicenseAccessor>() ?? new LicenseAccessor(
+                serviceProvider.GetRequiredService<MediatRServiceConfiguration>(),
+                serviceProvider.GetRequiredService<ILoggerFactory>()
+            );
+            var licenseValidator = serviceProvider.GetService<LicenseValidator>() 
+                                   ?? new LicenseValidator(serviceProvider.GetRequiredService<ILoggerFactory>());
+            
             var license = licenseAccessor.Current;
             licenseValidator.Validate(license);
         }
diff --git a/src/MediatR/Registration/ServiceRegistrar.cs b/src/MediatR/Registration/ServiceRegistrar.cs
index c2056c32..7f62cde6 100644
--- a/src/MediatR/Registration/ServiceRegistrar.cs
+++ b/src/MediatR/Registration/ServiceRegistrar.cs
@@ -391,6 +391,8 @@ public static void AddRequiredServices(IServiceCollection services, MediatRServi
         services.TryAdd(new ServiceDescriptor(typeof(IMediator), serviceConfiguration.MediatorImplementationType, serviceConfiguration.Lifetime));
         services.TryAdd(new ServiceDescriptor(typeof(ISender), sp => sp.GetRequiredService<IMediator>(), serviceConfiguration.Lifetime));
         services.TryAdd(new ServiceDescriptor(typeof(IPublisher), sp => sp.GetRequiredService<IMediator>(), serviceConfiguration.Lifetime));
+
+        MediatRServiceCollectionExtensions.LicenseChecked = false;
         
         services.TryAddSingleton(serviceConfiguration);
         services.TryAddSingleton<LicenseAccessor>();
diff --git a/test/MediatR.Tests/CreateStreamTests.cs b/test/MediatR.Tests/CreateStreamTests.cs
index 4139b75b..daa6bfd5 100644
--- a/test/MediatR.Tests/CreateStreamTests.cs
+++ b/test/MediatR.Tests/CreateStreamTests.cs
@@ -7,7 +7,6 @@ namespace MediatR.Tests;
 using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class CreateStreamTests
@@ -38,15 +37,13 @@ public async Task Should_resolve_main_handler()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(CreateStreamTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IStreamRequestHandler<,>));
+                scanner.FromAssemblyOf<CreateStreamTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IStreamRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = mediator.CreateStream(new Ping { Message = "Ping" });
         int i = 0;
@@ -70,15 +67,13 @@ public async Task Should_resolve_main_handler_via_dynamic_dispatch()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(CreateStreamTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IStreamRequestHandler<,>));
+                scanner.FromAssemblyOf<CreateStreamTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IStreamRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         object request = new Ping { Message = "Ping" };
         var response = mediator.CreateStream(request);
@@ -103,15 +98,13 @@ public async Task Should_resolve_main_handler_by_specific_interface()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(CreateStreamTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IStreamRequestHandler<,>));
+                scanner.FromAssemblyOf<CreateStreamTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IStreamRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<ISender>().Use<Mediator>();
+            cfg.AddTransient<ISender, Mediator>();
         });
 
-        var mediator = container.GetInstance<ISender>();
+        var mediator = container.GetRequiredService<ISender>();
         var response = mediator.CreateStream(new Ping { Message = "Ping" });
         int i = 0;
         await foreach (Pong result in response)
@@ -132,10 +125,10 @@ public void Should_raise_execption_on_null_request()
     {
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         Should.Throw<ArgumentNullException>(() => mediator.CreateStream((Ping) null!));
     }
@@ -145,10 +138,10 @@ public void Should_raise_execption_on_null_request_via_dynamic_dispatch()
     {
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         Should.Throw<ArgumentNullException>(() => mediator.CreateStream((object) null!));
     }
diff --git a/test/MediatR.Tests/ExceptionTests.cs b/test/MediatR.Tests/ExceptionTests.cs
index 7bf81aff..54108f72 100644
--- a/test/MediatR.Tests/ExceptionTests.cs
+++ b/test/MediatR.Tests/ExceptionTests.cs
@@ -5,9 +5,7 @@ namespace MediatR.Tests;
 using System;
 using System.Threading.Tasks;
 using Shouldly;
-using Lamar;
 using Xunit;
-using Lamar.IoC;
 
 public class ExceptionTests
 {
@@ -73,21 +71,21 @@ public ExceptionTests()
     {
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        _mediator = container.GetInstance<IMediator>();
+        _mediator = container.GetRequiredService<IMediator>();
     }
 
     [Fact]
     public async Task Should_throw_for_send()
     {
-        await Should.ThrowAsync<LamarMissingRegistrationException>(async () => await _mediator.Send(new Ping()));
+        await Should.ThrowAsync<InvalidOperationException>(async () => await _mediator.Send(new Ping()));
     }
 
     [Fact]
     public async Task Should_throw_for_void_send()
     {
-        await Should.ThrowAsync<LamarMissingRegistrationException>(async () => await _mediator.Send(new VoidPing()));
+        await Should.ThrowAsync<InvalidOperationException>(async () => await _mediator.Send(new VoidPing()));
     }
 
     [Fact]
@@ -108,13 +106,13 @@ public async Task Should_not_throw_for_publish()
     [Fact]
     public async Task Should_throw_for_async_send()
     {
-        await Should.ThrowAsync<LamarMissingRegistrationException>(async () => await _mediator.Send(new AsyncPing()));
+        await Should.ThrowAsync<InvalidOperationException>(async () => await _mediator.Send(new AsyncPing()));
     }
 
     [Fact]
     public async Task Should_throw_for_async_void_send()
     {
-        await Should.ThrowAsync<LamarMissingRegistrationException>(async () => await _mediator.Send(new AsyncVoidPing()));
+        await Should.ThrowAsync<InvalidOperationException>(async () => await _mediator.Send(new AsyncVoidPing()));
     }
 
     [Fact]
@@ -139,14 +137,12 @@ public async Task Should_throw_argument_exception_for_send_when_request_is_null(
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(NullPing));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<NullPing>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         NullPing request = null!;
 
@@ -160,14 +156,12 @@ public async Task Should_throw_argument_exception_for_void_send_when_request_is_
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(VoidNullPing));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<VoidNullPing>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         VoidNullPing request = null!;
 
@@ -181,14 +175,12 @@ public async Task Should_throw_argument_exception_for_publish_when_request_is_nu
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(NullPinged));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<NullPinged>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         NullPinged notification = null!;
 
@@ -202,14 +194,12 @@ public async Task Should_throw_argument_exception_for_publish_when_request_is_nu
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(NullPinged));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<NullPinged>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         object notification = null!;
 
@@ -223,14 +213,12 @@ public async Task Should_throw_argument_exception_for_publish_when_request_is_no
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(NullPinged));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<NullPinged>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         object notification = "totally not notification";
 
@@ -257,15 +245,13 @@ public async Task Should_throw_exception_for_non_generic_send_when_exception_occ
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(NullPinged));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
-                scanner.AddAllTypesOf(typeof(IRequestHandler<>));
+                scanner.FromAssemblyOf<NullPinged>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         object pingException = new PingException();
 
@@ -279,14 +265,12 @@ public async Task Should_throw_exception_for_non_request_send()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(NullPinged));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<NullPinged>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         object nonRequest = new NonRequest();
 
@@ -306,15 +290,13 @@ public async Task Should_throw_exception_for_generic_send_when_exception_occurs(
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(NullPinged));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
-                scanner.AddAllTypesOf(typeof(IRequestHandler<>));
+                scanner.FromAssemblyOf<NullPinged>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         PingException pingException = new PingException();
 
diff --git a/test/MediatR.Tests/GenericTypeConstraintsTests.cs b/test/MediatR.Tests/GenericTypeConstraintsTests.cs
index 3d3da79b..3846faa4 100644
--- a/test/MediatR.Tests/GenericTypeConstraintsTests.cs
+++ b/test/MediatR.Tests/GenericTypeConstraintsTests.cs
@@ -6,7 +6,6 @@ namespace MediatR.Tests;
 using System;
 using System.Linq;
 using Shouldly;
-using Lamar;
 using System.Threading.Tasks;
 using Xunit;
 
@@ -93,17 +92,14 @@ public GenericTypeConstraintsTests()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(GenericTypeConstraintsTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.IncludeNamespaceContainingType<Jing>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
-                scanner.AddAllTypesOf(typeof(IRequestHandler<>));
+                scanner.FromAssemblyOf<GenericTypeConstraintsTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        _mediator = container.GetInstance<IMediator>();
+        _mediator = container.GetRequiredService<IMediator>();
     }
 
     [Fact]
diff --git a/test/MediatR.Tests/MediatR.Tests.csproj b/test/MediatR.Tests/MediatR.Tests.csproj
index 6f405ac3..4ac61f57 100644
--- a/test/MediatR.Tests/MediatR.Tests.csproj
+++ b/test/MediatR.Tests/MediatR.Tests.csproj
@@ -6,23 +6,20 @@
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn);CS8002;</NoWarn>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>..\..\MediatR.snk</AssemblyOriginatorKeyFile>
   </PropertyGroup>
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\MediatR\MediatR.csproj"/>
   </ItemGroup>
 
-  <ItemGroup>
-    <Compile Include="..\..\src\MediatR\Licensing\**\*.cs" LinkBase="LicensingFiles" />
-  </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="IsExternalInit" Version="1.0.3">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Lamar" Version="8.1.0"  Condition="'$(TargetFramework)' == 'net481'" />
-    <PackageReference Include="Lamar" Version="13.1.0" Condition="'$(TargetFramework)' == 'net9.0'"/>
+    <PackageReference Include="Scrutor" Version="6.1.0" />
     <PackageReference Include="xunit" Version="2.6.1"/>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0"/>
     <PackageReference Include="Shouldly" Version="4.2.1"/>
diff --git a/test/MediatR.Tests/MicrosoftExtensionsDI/PipelineTests.cs b/test/MediatR.Tests/MicrosoftExtensionsDI/PipelineTests.cs
index f8c04223..fabc0ab1 100644
--- a/test/MediatR.Tests/MicrosoftExtensionsDI/PipelineTests.cs
+++ b/test/MediatR.Tests/MicrosoftExtensionsDI/PipelineTests.cs
@@ -395,6 +395,7 @@ public async Task Should_wrap_with_behavior()
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
         services.AddSingleton(output);
+        services.AddFakeLogging();
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly);
@@ -425,6 +426,7 @@ public async Task Should_wrap_generics_with_behavior()
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
         services.AddSingleton(output);
+        services.AddFakeLogging();
         services.AddMediatR(cfg =>
         {
             // Call these registration methods multiple times to prove we don't register a service if it is already registered
@@ -459,6 +461,7 @@ public async Task Should_register_pre_and_post_processors()
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
         services.AddSingleton(output);
+        services.AddFakeLogging();
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly);
@@ -498,6 +501,7 @@ public async Task Should_pick_up_specific_exception_behaviors()
     {
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
+        services.AddFakeLogging();
         services.AddSingleton(output);
         services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly));
         var provider = services.BuildServiceProvider();
@@ -534,6 +538,7 @@ public void Should_handle_exceptions_from_behaviors()
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
         services.AddSingleton(output);
+        services.AddFakeLogging();
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly);
@@ -554,6 +559,7 @@ public void Should_pick_up_exception_actions()
     {
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
+        services.AddFakeLogging();
         services.AddSingleton(output);
         services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly));
         var provider = services.BuildServiceProvider();
@@ -572,6 +578,7 @@ public async Task Should_handle_constrained_generics()
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
         services.AddSingleton(output);
+        services.AddFakeLogging();
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssembly(typeof(Ping).Assembly);
diff --git a/test/MediatR.Tests/MicrosoftExtensionsDI/StreamPipelineTests.cs b/test/MediatR.Tests/MicrosoftExtensionsDI/StreamPipelineTests.cs
index 9ca8fd1b..b0aa8318 100644
--- a/test/MediatR.Tests/MicrosoftExtensionsDI/StreamPipelineTests.cs
+++ b/test/MediatR.Tests/MicrosoftExtensionsDI/StreamPipelineTests.cs
@@ -60,6 +60,7 @@ public async Task Should_wrap_with_behavior()
     {
         var output = new Logger();
         IServiceCollection services = new ServiceCollection();
+        services.AddFakeLogging();
         services.AddSingleton(output);
         services.AddTransient<IStreamPipelineBehavior<StreamPing, Pong>, OuterBehavior>();
         services.AddTransient<IStreamPipelineBehavior<StreamPing, Pong>, InnerBehavior>();
diff --git a/test/MediatR.Tests/NotificationPublisherTests.cs b/test/MediatR.Tests/NotificationPublisherTests.cs
index a355a896..a41e7891 100644
--- a/test/MediatR.Tests/NotificationPublisherTests.cs
+++ b/test/MediatR.Tests/NotificationPublisherTests.cs
@@ -53,6 +53,7 @@ public async Task Should_handle_sequentially_by_default()
         var sequentialElapsed = timer.ElapsedMilliseconds;
 
         services = new ServiceCollection();
+        services.AddFakeLogging();
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssemblyContaining<Notification>();
diff --git a/test/MediatR.Tests/Pipeline/RequestExceptionActionTests.cs b/test/MediatR.Tests/Pipeline/RequestExceptionActionTests.cs
index 629859d7..5876d2b1 100644
--- a/test/MediatR.Tests/Pipeline/RequestExceptionActionTests.cs
+++ b/test/MediatR.Tests/Pipeline/RequestExceptionActionTests.cs
@@ -1,5 +1,4 @@
 using MediatR.Pipeline;
-using Lamar;
 
 namespace MediatR.Tests.Pipeline;
 
@@ -97,15 +96,15 @@ public async Task Should_run_all_exception_actions_that_match_base_type()
         
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IRequestHandler<Ping, Pong>>().Use<PingHandler>();
-            cfg.For<IRequestExceptionAction<Ping, PingException>>().Use(_ => pingExceptionAction);
-            cfg.For<IRequestExceptionAction<Ping, PingPongException>>().Use(_ => pingPongExceptionAction);
-            cfg.For<IRequestExceptionAction<Ping, PongException>>().Use(_ => pongExceptionAction);
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestExceptionActionProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IRequestHandler<Ping, Pong>, PingHandler>();
+            cfg.AddTransient<IRequestExceptionAction<Ping, PingException>>(_ => pingExceptionAction);
+            cfg.AddTransient<IRequestExceptionAction<Ping, PingPongException>>(_ => pingPongExceptionAction);
+            cfg.AddTransient<IRequestExceptionAction<Ping, PongException>>(_ => pongExceptionAction);
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestExceptionActionProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var request = new Ping { Message = "Ping!" };
         await Assert.ThrowsAsync<PingException>(() => mediator.Send(request));
@@ -121,13 +120,13 @@ public async Task Should_run_matching_exception_actions_only_once()
         var genericExceptionAction = new GenericExceptionAction<Ping>();
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IRequestHandler<Ping, Pong>>().Use<PingHandler>();
-            cfg.For<IRequestExceptionAction<Ping, Exception>>().Use(_ => genericExceptionAction);
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestExceptionActionProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IRequestHandler<Ping, Pong>, PingHandler>();
+            cfg.AddTransient<IRequestExceptionAction<Ping, Exception>>(_ => genericExceptionAction);
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestExceptionActionProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var request = new Ping { Message = "Ping!" };
         await Assert.ThrowsAsync<PingException>(() => mediator.Send(request));
diff --git a/test/MediatR.Tests/Pipeline/RequestExceptionHandlerTests.cs b/test/MediatR.Tests/Pipeline/RequestExceptionHandlerTests.cs
index aef3c346..3b7409f9 100644
--- a/test/MediatR.Tests/Pipeline/RequestExceptionHandlerTests.cs
+++ b/test/MediatR.Tests/Pipeline/RequestExceptionHandlerTests.cs
@@ -5,7 +5,6 @@ namespace MediatR.Tests.Pipeline;
 using System.Threading.Tasks;
 using MediatR.Pipeline;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class RequestExceptionHandlerTests
@@ -89,14 +88,14 @@ public async Task Should_run_exception_handler_and_allow_for_exception_not_to_th
     {
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IRequestHandler<Ping, Pong>>().Use<PingHandler>();
-            cfg.For<IRequestExceptionHandler<Ping, Pong, Exception>>().Use<PingPongExceptionHandler>();
-            cfg.For<IRequestExceptionHandler<Ping, Pong, PingException>>().Use<PingPongExceptionHandlerForType>();
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestExceptionProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IRequestHandler<Ping, Pong>, PingHandler>();
+            cfg.AddTransient<IRequestExceptionHandler<Ping, Pong, Exception>, PingPongExceptionHandler>();
+            cfg.AddTransient<IRequestExceptionHandler<Ping, Pong, PingException>, PingPongExceptionHandlerForType>();
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestExceptionProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = await mediator.Send(new Ping { Message = "Ping" });
 
@@ -108,13 +107,13 @@ public async Task Should_run_exception_handler_and_allow_for_exception_to_be_sti
     {
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IRequestHandler<Ping, Pong>>().Use<PingHandler>();
-            cfg.For<IRequestExceptionHandler<Ping, Pong, Exception>>().Use<PingPongExceptionHandlerNotHandled>();
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestExceptionProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IRequestHandler<Ping, Pong>, PingHandler>();
+            cfg.AddTransient<IRequestExceptionHandler<Ping, Pong, Exception>, PingPongExceptionHandlerNotHandled>();
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestExceptionProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var request = new Ping { Message = "Ping" };
         await Should.ThrowAsync<PingException>(async () =>
@@ -130,13 +129,13 @@ public async Task Should_run_exception_handler_and_unwrap_expections_thrown_in_t
     {
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IRequestHandler<Ping, Pong>>().Use<PingHandler>();
-            cfg.For<IRequestExceptionHandler<Ping, Pong, Exception>>().Use<PingPongThrowingExceptionHandler>();
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestExceptionProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IRequestHandler<Ping, Pong>, PingHandler>();
+            cfg.AddTransient<IRequestExceptionHandler<Ping, Pong, Exception>, PingPongThrowingExceptionHandler>();
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestExceptionProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var request = new Ping { Message = "Ping" };
         await Should.ThrowAsync<ApplicationException>(async () =>
@@ -151,13 +150,13 @@ public async Task Should_run_matching_exception_handlers_only_once()
         var genericPingExceptionHandler = new GenericPingExceptionHandler();
         var container = TestContainer.Create(cfg =>
         {
-            cfg.For<IRequestHandler<Ping, Pong>>().Use<PingHandler>();
-            cfg.For<IRequestExceptionHandler<Ping, Pong, Exception>>().Use(genericPingExceptionHandler);
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestExceptionProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IRequestHandler<Ping, Pong>, PingHandler>();
+            cfg.AddSingleton<IRequestExceptionHandler<Ping, Pong, Exception>>(genericPingExceptionHandler);
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestExceptionProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var request = new Ping { Message = "Ping" };
         await Should.ThrowAsync<PingException>(async () =>
diff --git a/test/MediatR.Tests/Pipeline/RequestPostProcessorTests.cs b/test/MediatR.Tests/Pipeline/RequestPostProcessorTests.cs
index 73a854e5..3f2f9f6c 100644
--- a/test/MediatR.Tests/Pipeline/RequestPostProcessorTests.cs
+++ b/test/MediatR.Tests/Pipeline/RequestPostProcessorTests.cs
@@ -5,7 +5,6 @@ namespace MediatR.Tests.Pipeline;
 using System.Threading.Tasks;
 using MediatR.Pipeline;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class RequestPostProcessorTests
@@ -45,17 +44,14 @@ public async Task Should_run_postprocessors()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
-                scanner.AddAllTypesOf(typeof(IRequestPostProcessor<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>()).AsImplementedInterfaces();
             });
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestPostProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestPostProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = await mediator.Send(new Ping { Message = "Ping" });
 
diff --git a/test/MediatR.Tests/Pipeline/RequestPreProcessorTests.cs b/test/MediatR.Tests/Pipeline/RequestPreProcessorTests.cs
index a868b60f..11e5b604 100644
--- a/test/MediatR.Tests/Pipeline/RequestPreProcessorTests.cs
+++ b/test/MediatR.Tests/Pipeline/RequestPreProcessorTests.cs
@@ -5,7 +5,6 @@ namespace MediatR.Tests.Pipeline;
 using System.Threading.Tasks;
 using MediatR.Pipeline;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class RequestPreProcessorTests
@@ -45,17 +44,14 @@ public async Task Should_run_preprocessors()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
-                scanner.AddAllTypesOf(typeof(IRequestPreProcessor<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>()).AsImplementedInterfaces();
             });
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(RequestPreProcessorBehavior<,>));
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(RequestPreProcessorBehavior<,>));
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = await mediator.Send(new Ping { Message = "Ping" });
 
diff --git a/test/MediatR.Tests/Pipeline/Streams/StreamPipelineBehaviorTests.cs b/test/MediatR.Tests/Pipeline/Streams/StreamPipelineBehaviorTests.cs
index 3145f320..8562284a 100644
--- a/test/MediatR.Tests/Pipeline/Streams/StreamPipelineBehaviorTests.cs
+++ b/test/MediatR.Tests/Pipeline/Streams/StreamPipelineBehaviorTests.cs
@@ -5,7 +5,6 @@
 namespace MediatR.Tests.Pipeline.Streams;
 
 using Shouldly;
-using Lamar;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
diff --git a/test/MediatR.Tests/PipelineTests.cs b/test/MediatR.Tests/PipelineTests.cs
index 33a5b1b9..79983886 100644
--- a/test/MediatR.Tests/PipelineTests.cs
+++ b/test/MediatR.Tests/PipelineTests.cs
@@ -5,7 +5,6 @@ namespace MediatR.Tests;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class PipelineTests
@@ -248,18 +247,16 @@ public async Task Should_wrap_with_behavior()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
-            cfg.For<IPipelineBehavior<Ping, Pong>>().Add<OuterBehavior>();
-            cfg.For<IPipelineBehavior<Ping, Pong>>().Add<InnerBehavior>();
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddSingleton<Logger>(output);
+            cfg.AddTransient<IPipelineBehavior<Ping, Pong>, OuterBehavior>();
+            cfg.AddTransient<IPipelineBehavior<Ping, Pong>, InnerBehavior>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = await mediator.Send(new Ping { Message = "Ping" });
 
@@ -283,18 +280,16 @@ public async Task Should_wrap_void_with_behavior()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
-            cfg.For<IPipelineBehavior<VoidPing, Unit>>().Add<OuterVoidBehavior>();
-            cfg.For<IPipelineBehavior<VoidPing, Unit>>().Add<InnerVoidBehavior>();
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddSingleton<Logger>(output);
+            cfg.AddTransient<IPipelineBehavior<VoidPing, Unit>, OuterVoidBehavior>();
+            cfg.AddTransient<IPipelineBehavior<VoidPing, Unit>, InnerVoidBehavior>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await mediator.Send(new VoidPing { Message = "Ping" });
 
@@ -316,20 +311,18 @@ public async Task Should_wrap_generics_with_behavior()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
+            cfg.AddSingleton<Logger>(output);
 
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(OuterBehavior<,>));
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(InnerBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(OuterBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(InnerBehavior<,>));
 
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = await mediator.Send(new Ping { Message = "Ping" });
 
@@ -353,21 +346,19 @@ public async Task Should_wrap_void_generics_with_behavior()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
-                scanner.AddAllTypesOf(typeof(IRequestHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
+            cfg.AddSingleton<Logger>(output);
 
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(OuterBehavior<,>));
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(InnerBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(OuterBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(InnerBehavior<,>));
 
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await mediator.Send(new VoidPing { Message = "Ping" });
 
@@ -389,23 +380,21 @@ public async Task Should_handle_constrained_generics()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
+            cfg.AddSingleton<Logger>(output);
 
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(OuterBehavior<,>));
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(InnerBehavior<,>));
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(ConstrainedBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(OuterBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(InnerBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(ConstrainedBehavior<,>));
 
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        container.GetAllInstances<IPipelineBehavior<Ping, Pong>>();
+        //container.GetAllInstances<IPipelineBehavior<Ping, Pong>>();
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = await mediator.Send(new Ping { Message = "Ping" });
 
@@ -446,23 +435,22 @@ public async Task Should_handle_concrete_and_open_generics()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>()).AsImplementedInterfaces()
+                    .AddClasses(t => t.AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
+            cfg.AddSingleton<Logger>(output);
 
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(OuterBehavior<,>));
-            cfg.For(typeof(IPipelineBehavior<,>)).Add(typeof(InnerBehavior<,>));
-            cfg.For(typeof(IPipelineBehavior<Ping, Pong>)).Add(typeof(ConcreteBehavior));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(OuterBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<,>), typeof(InnerBehavior<,>));
+            cfg.AddTransient(typeof(IPipelineBehavior<Ping, Pong>), typeof(ConcreteBehavior));
 
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        container.GetAllInstances<IPipelineBehavior<Ping, Pong>>();
+        //container.GetAllInstances<IPipelineBehavior<Ping, Pong>>();
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         var response = await mediator.Send(new Ping { Message = "Ping" });
 
diff --git a/test/MediatR.Tests/PublishTests.cs b/test/MediatR.Tests/PublishTests.cs
index 1fae4b9c..8d0e85ea 100644
--- a/test/MediatR.Tests/PublishTests.cs
+++ b/test/MediatR.Tests/PublishTests.cs
@@ -8,7 +8,6 @@ namespace MediatR.Tests;
 using System.Text;
 using System.Threading.Tasks;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class PublishTests
@@ -58,16 +57,14 @@ public async Task Should_resolve_main_handler()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof (INotificationHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(INotificationHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<TextWriter>().Use(writer);
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddSingleton<TextWriter>(writer);
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await mediator.Publish(new Ping { Message = "Ping" });
 
@@ -86,16 +83,14 @@ public async Task Should_resolve_main_handler_when_object_is_passed()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof (INotificationHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(INotificationHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<TextWriter>().Use(writer);
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddSingleton<TextWriter>(writer);
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         object message = new Ping { Message = "Ping" };
         await mediator.Publish(message);
@@ -145,16 +140,14 @@ public async Task Should_override_with_sequential_firing()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(INotificationHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(INotificationHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<TextWriter>().Use(writer);
-            cfg.For<IMediator>().Use<SequentialMediator>();
+            cfg.AddSingleton<TextWriter>(writer);
+            cfg.AddTransient<IMediator, SequentialMediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await mediator.Publish(new Ping { Message = "Ping" });
 
@@ -174,17 +167,15 @@ public async Task Should_override_with_sequential_firing_through_injection()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(INotificationHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(INotificationHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<TextWriter>().Use(writer);
-            cfg.For<INotificationPublisher>().Use(publisher);
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddSingleton<TextWriter>(writer);
+            cfg.AddSingleton<INotificationPublisher>(publisher);
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await mediator.Publish(new Ping { Message = "Ping" });
 
@@ -204,16 +195,14 @@ public async Task Should_resolve_handlers_given_interface()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(INotificationHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(INotificationHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<TextWriter>().Use(writer);
-            cfg.For<IMediator>().Use<SequentialMediator>();
+            cfg.AddSingleton<TextWriter>(writer);
+            cfg.AddTransient<IMediator, SequentialMediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         // wrap notifications in an array, so this test won't break on a 'replace with var' refactoring
         var notifications = new INotification[] { new Ping { Message = "Ping" } };
@@ -234,16 +223,14 @@ public async Task Should_resolve_main_handler_by_specific_interface()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof (INotificationHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(INotificationHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<TextWriter>().Use(writer);
-            cfg.For<IPublisher>().Use<Mediator>();
+            cfg.AddSingleton<TextWriter>(writer);
+            cfg.AddTransient<IPublisher, Mediator>();
         });
 
-        var mediator = container.GetInstance<IPublisher>();
+        var mediator = container.GetRequiredService<IPublisher>();
 
         await mediator.Publish(new Ping { Message = "Ping" });
 
diff --git a/test/MediatR.Tests/SendTests.cs b/test/MediatR.Tests/SendTests.cs
index 81b64285..8fec7d3a 100644
--- a/test/MediatR.Tests/SendTests.cs
+++ b/test/MediatR.Tests/SendTests.cs
@@ -305,6 +305,7 @@ public async Task Should_resolve_closed_handler_if_defined()
         var dependency = new Dependency();
         var services = new ServiceCollection();
         services.AddSingleton(dependency);
+        services.AddFakeLogging();
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssemblies(Assembly.GetExecutingAssembly());
@@ -327,6 +328,7 @@ public async Task Should_resolve_open_handler_if_not_defined()
     {
         var dependency = new Dependency();
         var services = new ServiceCollection();
+        services.AddFakeLogging();
         services.AddSingleton(dependency);
         services.AddMediatR(cfg => 
         {
diff --git a/test/MediatR.Tests/SendVoidInterfaceTests.cs b/test/MediatR.Tests/SendVoidInterfaceTests.cs
index ed5e537c..60ca6bb4 100644
--- a/test/MediatR.Tests/SendVoidInterfaceTests.cs
+++ b/test/MediatR.Tests/SendVoidInterfaceTests.cs
@@ -6,7 +6,6 @@ namespace MediatR.Tests;
 using System.Text;
 using System.Threading.Tasks;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class SendVoidInterfaceTests
@@ -36,18 +35,16 @@ public async Task Should_resolve_main_void_handler()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof (IRequestHandler<,>));
-                scanner.AddAllTypesOf(typeof (IRequestHandler<>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<,>))).AsImplementedInterfaces()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IRequestHandler<>))).AsImplementedInterfaces();
             });
-            cfg.For<TextWriter>().Use(writer);
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddSingleton<TextWriter>(writer);
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await mediator.Send(new Ping { Message = "Ping" });
 
diff --git a/test/MediatR.Tests/ServiceFactoryTests.cs b/test/MediatR.Tests/ServiceFactoryTests.cs
index dff293e3..aaaf989d 100644
--- a/test/MediatR.Tests/ServiceFactoryTests.cs
+++ b/test/MediatR.Tests/ServiceFactoryTests.cs
@@ -9,6 +9,10 @@
 
 namespace MediatR.Tests;
 
+[CollectionDefinition(nameof(ServiceFactoryCollectionBehavior), DisableParallelization = true)]
+public class ServiceFactoryCollectionBehavior {}
+
+[Collection(nameof(ServiceFactoryCollectionBehavior))]
 public class ServiceFactoryTests
 {
     public class Ping : IRequest<Pong>
@@ -24,6 +28,8 @@ public class Pong
     [Fact]
     public async Task Should_throw_given_no_handler()
     {
+        MediatRServiceCollectionExtensions.LicenseChecked = false;
+      
         var serviceCollection = new ServiceCollection();
         ServiceRegistrar.AddRequiredServices(serviceCollection, new MediatRServiceConfiguration());
         serviceCollection.AddFakeLogging();
@@ -36,4 +42,33 @@ await Assert.ThrowsAsync<InvalidOperationException>(
             () => mediator.Send(new Ping())
         );
     }
+
+    [Fact]
+    public void Should_not_throw_with_manual_registration()
+    {
+        MediatRServiceCollectionExtensions.LicenseChecked = false;
+      
+        var services = new ServiceCollection();
+        services.AddFakeLogging();
+        services.AddTransient<IMediator, Mediator>();
+        services.AddSingleton(new MediatRServiceConfiguration());
+
+        var container = services.BuildServiceProvider();
+
+        Should.NotThrow(() => container.GetRequiredService<IMediator>());
+    }
+    
+    [Fact]
+    public void Should_throw_when_missing_required_configuration()
+    {
+        MediatRServiceCollectionExtensions.LicenseChecked = false;
+        
+        var services = new ServiceCollection();
+        services.AddFakeLogging();
+        services.AddTransient<IMediator, Mediator>();
+
+        var container = services.BuildServiceProvider();
+
+        Should.Throw<InvalidOperationException>(() => container.GetRequiredService<IMediator>());
+    }
 }
\ No newline at end of file
diff --git a/test/MediatR.Tests/StreamPipelineTests.cs b/test/MediatR.Tests/StreamPipelineTests.cs
index 67242441..8e0a93db 100644
--- a/test/MediatR.Tests/StreamPipelineTests.cs
+++ b/test/MediatR.Tests/StreamPipelineTests.cs
@@ -6,7 +6,6 @@ namespace MediatR.Tests;
 using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 using Shouldly;
-using Lamar;
 using Xunit;
 
 public class StreamPipelineTests
@@ -199,18 +198,16 @@ public async Task Should_wrap_with_behavior()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IStreamRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IStreamRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
-            cfg.For<IStreamPipelineBehavior<Ping, Pong>>().Add<OuterBehavior>();
-            cfg.For<IStreamPipelineBehavior<Ping, Pong>>().Add<InnerBehavior>();
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddSingleton<Logger>(output);
+            cfg.AddTransient<IStreamPipelineBehavior<Ping, Pong>, OuterBehavior>();
+            cfg.AddTransient<IStreamPipelineBehavior<Ping, Pong>, InnerBehavior>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await foreach(var response in mediator.CreateStream(new Ping { Message = "Ping" }))
         {
@@ -235,20 +232,18 @@ public async Task Should_wrap_generics_with_behavior()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IStreamRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IStreamRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
+            cfg.AddSingleton<Logger>(output);
 
-            cfg.For(typeof(IStreamPipelineBehavior<,>)).Add(typeof(OuterBehavior<,>));
-            cfg.For(typeof(IStreamPipelineBehavior<,>)).Add(typeof(InnerBehavior<,>));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<,>), typeof(OuterBehavior<,>));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<,>), typeof(InnerBehavior<,>));
 
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await foreach (var response in mediator.CreateStream(new Ping { Message = "Ping" }))
         {
@@ -273,21 +268,19 @@ public async Task Should_handle_constrained_generics()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IStreamRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>().AssignableTo(typeof(IStreamRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
+            cfg.AddSingleton<Logger>(output);
 
-            cfg.For(typeof(IStreamPipelineBehavior<,>)).Add(typeof(OuterBehavior<,>));
-            cfg.For(typeof(IStreamPipelineBehavior<,>)).Add(typeof(InnerBehavior<,>));
-            cfg.For(typeof(IStreamPipelineBehavior<,>)).Add(typeof(ConstrainedBehavior<,>));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<,>), typeof(OuterBehavior<,>));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<,>), typeof(InnerBehavior<,>));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<,>), typeof(ConstrainedBehavior<,>));
 
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await foreach (var response in mediator.CreateStream(new Ping { Message = "Ping" }))
         {
@@ -330,21 +323,20 @@ public async Task Should_handle_concrete_and_open_generics()
         {
             cfg.Scan(scanner =>
             {
-                scanner.AssemblyContainingType(typeof(PublishTests));
-                scanner.IncludeNamespaceContainingType<Ping>();
-                scanner.WithDefaultConventions();
-                scanner.AddAllTypesOf(typeof(IStreamRequestHandler<,>));
+                scanner.FromAssemblyOf<PublishTests>()
+                    .AddClasses(t => t.InNamespaceOf<Ping>()).AsImplementedInterfaces()
+                    .AddClasses(t => t.AssignableTo(typeof(IStreamRequestHandler<,>))).AsImplementedInterfaces();
             });
-            cfg.For<Logger>().Use(output);
+            cfg.AddSingleton<Logger>(output);
 
-            cfg.For(typeof(IStreamPipelineBehavior<,>)).Add(typeof(OuterBehavior<,>));
-            cfg.For(typeof(IStreamPipelineBehavior<,>)).Add(typeof(InnerBehavior<,>));
-            cfg.For(typeof(IStreamPipelineBehavior<Ping, Pong>)).Add(typeof(ConcreteBehavior));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<,>), typeof(OuterBehavior<,>));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<,>), typeof(InnerBehavior<,>));
+            cfg.AddTransient(typeof(IStreamPipelineBehavior<Ping, Pong>), typeof(ConcreteBehavior));
 
-            cfg.For<IMediator>().Use<Mediator>();
+            cfg.AddTransient<IMediator, Mediator>();
         });
 
-        var mediator = container.GetInstance<IMediator>();
+        var mediator = container.GetRequiredService<IMediator>();
 
         await foreach (var response in mediator.CreateStream(new Ping { Message = "Ping" }))
         {
diff --git a/test/MediatR.Tests/TestContainer.cs b/test/MediatR.Tests/TestContainer.cs
index 2baa72de..dfa2e5c6 100644
--- a/test/MediatR.Tests/TestContainer.cs
+++ b/test/MediatR.Tests/TestContainer.cs
@@ -1,4 +1,3 @@
-using Lamar;
 using MediatR.Licensing;
 using MediatR.Registration;
 using Microsoft.Extensions.Logging;
@@ -8,18 +7,23 @@ namespace MediatR.Tests;
 
 public static class TestContainer
 {
-    public static Container Create(Action<ServiceRegistry> config)
+    public static IServiceProvider Create(Action<ServiceCollection> config)
     {
-        Action<ServiceRegistry> configAction = cfg =>
+        var services = new ServiceCollection();
+        
+        ConfigAction(services);
+
+        var container = services.BuildServiceProvider();
+
+        return container;
+
+        void ConfigAction(ServiceCollection cfg)
         {
-            cfg.ForSingletonOf<ILoggerFactory>().Use(new NullLoggerFactory());
-            
+            cfg.AddSingleton<ILoggerFactory, NullLoggerFactory>();
+
             ServiceRegistrar.AddRequiredServices(cfg, new MediatRServiceConfiguration());
 
             config(cfg);
-        };
-        var container = new Container(configAction);
-
-        return container;
+        }
     } 
 }
\ No newline at end of file