diff --git a/src/MediatR.Extensions.Microsoft.DependencyInjection/Registration/ServiceRegistrar.cs b/src/MediatR.Extensions.Microsoft.DependencyInjection/Registration/ServiceRegistrar.cs
index 6c9b260..ae9d048 100644
--- a/src/MediatR.Extensions.Microsoft.DependencyInjection/Registration/ServiceRegistrar.cs
+++ b/src/MediatR.Extensions.Microsoft.DependencyInjection/Registration/ServiceRegistrar.cs
@@ -10,7 +10,11 @@ namespace MediatR.Registration
 {
     public static class ServiceRegistrar
     {
-        public static void AddMediatRClasses(IServiceCollection services, IEnumerable<Assembly> assembliesToScan)
+
+        public static void AddMediatRClasses(this IServiceCollection services, params Assembly[] assembliesToScan)
+            => services.AddMediatRClasses((IEnumerable<Assembly>) assembliesToScan);
+
+        public static void AddMediatRClasses(this IServiceCollection services, IEnumerable<Assembly> assembliesToScan)
         {
             assembliesToScan = (assembliesToScan as Assembly[] ?? assembliesToScan).Distinct().ToArray();
 
diff --git a/src/MediatR.Extensions.Microsoft.DependencyInjection/ServiceCollectionExtensions.cs b/src/MediatR.Extensions.Microsoft.DependencyInjection/ServiceCollectionExtensions.cs
index 41c3133..bc60d89 100644
--- a/src/MediatR.Extensions.Microsoft.DependencyInjection/ServiceCollectionExtensions.cs
+++ b/src/MediatR.Extensions.Microsoft.DependencyInjection/ServiceCollectionExtensions.cs
@@ -19,6 +19,15 @@ namespace MediatR
     /// </summary>
     public static class ServiceCollectionExtensions
     {
+        /// <summary>
+        /// Registers mediator types only. Handlers must be registered separately, possibly with <see cref="AddMediatRClasses(IServiceCollection, Assembly[])"/>.
+        /// </summary>
+        /// <param name="services">Service collection</param>
+        /// <returns>Service collection</returns>
+        public static IServiceCollection AddMediatR(this IServiceCollection services)
+            => services.AddMediatR(new Assembly[0], configuration: null);
+
+
         /// <summary>
         /// Registers handlers and mediator types from the specified assemblies
         /// </summary>
@@ -47,10 +56,6 @@ public static IServiceCollection AddMediatR(this IServiceCollection services, Ac
         /// <returns>Service collection</returns>
         public static IServiceCollection AddMediatR(this IServiceCollection services, IEnumerable<Assembly> assemblies, Action<MediatRServiceConfiguration> configuration)
         {
-            if (!assemblies.Any())
-            {
-                throw new ArgumentException("No assemblies found to scan. Supply at least one assembly to scan for handlers.");
-            }
             var serviceConfig = new MediatRServiceConfiguration();
 
             configuration?.Invoke(serviceConfig);
diff --git a/test/MediatR.Extensions.Microsoft.DependencyInjection.Tests/AssemblyResolutionTests.cs b/test/MediatR.Extensions.Microsoft.DependencyInjection.Tests/AssemblyResolutionTests.cs
index b5a352d..bd69511 100644
--- a/test/MediatR.Extensions.Microsoft.DependencyInjection.Tests/AssemblyResolutionTests.cs
+++ b/test/MediatR.Extensions.Microsoft.DependencyInjection.Tests/AssemblyResolutionTests.cs
@@ -1,8 +1,10 @@
-using Microsoft.Extensions.DependencyInjection;
+using MediatR.Registration;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace MediatR.Extensions.Microsoft.DependencyInjection.Tests
 {
     using System;
+    using System.Collections.Generic;
     using System.Linq;
     using System.Reflection;
     using Shouldly;
@@ -45,13 +47,33 @@ public void ShouldResolveNotificationHandlers()
         }
 
         [Fact]
-        public void ShouldRequireAtLeastOneAssembly()
+        public void ShouldNotRequireAtLeastOneAssembly()
         {
             var services = new ServiceCollection();
 
             Action registration = () => services.AddMediatR(new Type[0]);
 
-            registration.ShouldThrow<ArgumentException>();
+            registration.ShouldNotThrow();
+        }
+
+        [Fact]
+        public void ShouldResolveHandlerWithParamsRegistration()
+        {
+            var services = new ServiceCollection();
+            services.AddMediatR();
+            services.AddMediatRClasses(typeof(Ping).GetTypeInfo().Assembly);
+
+            _provider.GetService<IRequestHandler<Ping, Pong>>().ShouldNotBeNull();
+        }
+
+        [Fact]
+        public void ShouldResolveHandlerWithEnumerableRegistration()
+        {
+            var services = new ServiceCollection();
+            services.AddMediatR();
+            services.AddMediatRClasses(new List<Assembly>() { typeof(Ping).GetTypeInfo().Assembly });
+
+            _provider.GetService<IRequestHandler<Ping, Pong>>().ShouldNotBeNull();
         }
     }
 }
\ No newline at end of file