diff --git a/src/Cnblogs.Architecture.Ddd.Cqrs.AspNetCore/ApiControllerBase.cs b/src/Cnblogs.Architecture.Ddd.Cqrs.AspNetCore/ApiControllerBase.cs
index 78fbe03..2d11543 100644
--- a/src/Cnblogs.Architecture.Ddd.Cqrs.AspNetCore/ApiControllerBase.cs
+++ b/src/Cnblogs.Architecture.Ddd.Cqrs.AspNetCore/ApiControllerBase.cs
@@ -52,7 +52,7 @@ protected IActionResult HandleCommandResponse<TResponse, TError>(CommandResponse
     {
         if (response.IsSuccess())
         {
-            return Request.Headers.CqrsVersion() > 1 ? Ok(response) : Ok(response.Response);
+            return Request.Headers.CqrsVersion() > 1 ? new CqrsObjectResult(response) : Ok(response.Response);
         }
 
         return HandleCommandResponse((CommandResponse<TError>)response);
diff --git a/src/Cnblogs.Architecture.Ddd.Cqrs.DependencyInjection/ServiceCollectionInjector.cs b/src/Cnblogs.Architecture.Ddd.Cqrs.DependencyInjection/ServiceCollectionInjector.cs
index 6db17e7..64b92af 100644
--- a/src/Cnblogs.Architecture.Ddd.Cqrs.DependencyInjection/ServiceCollectionInjector.cs
+++ b/src/Cnblogs.Architecture.Ddd.Cqrs.DependencyInjection/ServiceCollectionInjector.cs
@@ -1,5 +1,4 @@
 using System.Reflection;
-
 using Cnblogs.Architecture.Ddd.Cqrs.Abstractions;
 using Cnblogs.Architecture.Ddd.Cqrs.DependencyInjection;
 using MediatR;
@@ -22,6 +21,12 @@ public static CqrsInjector AddCqrs(this IServiceCollection services, params Asse
     {
         services.AddTransient(typeof(IPipelineBehavior<,>), typeof(ValidationBehavior<,>));
         services.AddTransient(typeof(IPipelineBehavior<,>), typeof(LoggingBehavior<,>));
+        if (assemblies.Length == 0)
+        {
+            // mediator needs at least one assembly to inject from
+            assemblies = [typeof(CqrsInjector).Assembly];
+        }
+
         services.AddMediatR(cfg => cfg.RegisterServicesFromAssemblies(assemblies));
         return new CqrsInjector(services);
     }
diff --git a/test/Cnblogs.Architecture.IntegrationTests/CommandResponseHandlerTests.cs b/test/Cnblogs.Architecture.IntegrationTests/CommandResponseHandlerTests.cs
index 145eb5b..28cea2e 100644
--- a/test/Cnblogs.Architecture.IntegrationTests/CommandResponseHandlerTests.cs
+++ b/test/Cnblogs.Architecture.IntegrationTests/CommandResponseHandlerTests.cs
@@ -53,6 +53,7 @@ public async Task MinimalApi_CqrsV2_CommandResponseAsync()
         var content = await response.Content.ReadFromJsonAsync<CommandResponse<string, TestError>>();
 
         // Assert
+        response.Headers.CqrsVersion().Should().BeGreaterThan(1);
         content.Should().NotBeNull();
         content!.Response.Should().NotBeNullOrEmpty();
     }
@@ -89,7 +90,8 @@ public async Task Mvc_CurrentCqrsVersion_CommandResponseAsync()
 
         // Assert
         response.Should().BeSuccessful();
-        content!.Response.Should().NotBeNull();
+        response.Headers.CqrsVersion().Should().BeGreaterThan(1);
+        content!.Response.Should().NotBeNullOrEmpty();
     }
 
     [Theory]
diff --git a/test/Cnblogs.Architecture.IntegrationTests/DaprTests.cs b/test/Cnblogs.Architecture.IntegrationTests/DaprTests.cs
index a017ad5..8930ffd 100644
--- a/test/Cnblogs.Architecture.IntegrationTests/DaprTests.cs
+++ b/test/Cnblogs.Architecture.IntegrationTests/DaprTests.cs
@@ -21,7 +21,7 @@ public async Task Dapr_SubscribeEndpoint_OkAsync(SubscribeType subscribeType)
     {
         // Arrange
         var builder = WebApplication.CreateBuilder();
-        builder.Services.AddEventBus(o => o.UseDapr(nameof(DaprTests)));
+        builder.Services.AddCqrs(typeof(TestIntegrationEvent).Assembly).AddEventBus(o => o.UseDapr(nameof(DaprTests)));
         builder.WebHost.UseTestServer();
 
         await using var app = builder.Build();
@@ -53,7 +53,7 @@ public async Task Dapr_SubscribeWithoutAnyAssembly_OkAsync()
     {
         // Arrange
         var builder = WebApplication.CreateBuilder();
-        builder.Services.AddEventBus(o => o.UseDapr(nameof(DaprTests)));
+        builder.Services.AddCqrs().AddEventBus(o => o.UseDapr(nameof(DaprTests)));
         builder.WebHost.UseTestServer();
 
         var app = builder.Build();
diff --git a/test/Cnblogs.Architecture.UnitTests/EventBus/AssemblyAttributeTests.cs b/test/Cnblogs.Architecture.UnitTests/EventBus/AssemblyAttributeTests.cs
index 3ad6a62..47325a3 100644
--- a/test/Cnblogs.Architecture.UnitTests/EventBus/AssemblyAttributeTests.cs
+++ b/test/Cnblogs.Architecture.UnitTests/EventBus/AssemblyAttributeTests.cs
@@ -3,6 +3,7 @@
 using Cnblogs.Architecture.TestIntegrationEvents;
 using FluentAssertions;
 using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Cnblogs.Architecture.UnitTests.EventBus;
 
@@ -13,7 +14,7 @@ public void SubscribeByAssemblyMeta_Success()
     {
         // Arrange
         var builder = WebApplication.CreateBuilder();
-        builder.Services.AddEventBus(o => o.UseDapr(nameof(AssemblyAttributeTests)));
+        builder.Services.AddCqrs().AddEventBus(o => o.UseDapr(nameof(AssemblyAttributeTests)));
         var app = builder.Build();
 
         // Act