diff --git a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
index 020052115a..783dbb1082 100644
--- a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
+++ b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntime.cs
@@ -42,41 +42,6 @@ namespace Microsoft.JSInterop.WebAssembly
             BeginInvokeJS(0, "DotNet.jsCallDispatcher.endInvokeDotNetFromJS", args);
         }
 
-        #region Custom WebAssemblyJSRuntime methods
-
-        /// <summary>
-        /// Invokes the JavaScript function registered with the specified identifier.
-        /// </summary>
-        /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-        /// <param name="identifier">The identifier used when registering the target function.</param>
-        /// <returns>The result of the function invocation.</returns>
-        public TResult InvokeUnmarshalled<TResult>(string identifier)
-            => InvokeUnmarshalled<object, object, object, TResult>(identifier, null, null, null);
-
-        /// <summary>
-        /// Invokes the JavaScript function registered with the specified identifier.
-        /// </summary>
-        /// <typeparam name="T0">The type of the first argument.</typeparam>
-        /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-        /// <param name="identifier">The identifier used when registering the target function.</param>
-        /// <param name="arg0">The first argument.</param>
-        /// <returns>The result of the function invocation.</returns>
-        public TResult InvokeUnmarshalled<T0, TResult>(string identifier, T0 arg0)
-            => InvokeUnmarshalled<T0, object, object, TResult>(identifier, arg0, null, null);
-
-        /// <summary>
-        /// Invokes the JavaScript function registered with the specified identifier.
-        /// </summary>
-        /// <typeparam name="T0">The type of the first argument.</typeparam>
-        /// <typeparam name="T1">The type of the second argument.</typeparam>
-        /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
-        /// <param name="identifier">The identifier used when registering the target function.</param>
-        /// <param name="arg0">The first argument.</param>
-        /// <param name="arg1">The second argument.</param>
-        /// <returns>The result of the function invocation.</returns>
-        public TResult InvokeUnmarshalled<T0, T1, TResult>(string identifier, T0 arg0, T1 arg1)
-            => InvokeUnmarshalled<T0, T1, object, TResult>(identifier, arg0, arg1, null);
-
         /// <summary>
         /// Invokes the JavaScript function registered with the specified identifier.
         /// </summary>
@@ -89,14 +54,12 @@ namespace Microsoft.JSInterop.WebAssembly
         /// <param name="arg1">The second argument.</param>
         /// <param name="arg2">The third argument.</param>
         /// <returns>The result of the function invocation.</returns>
-        public TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2)
+        public virtual TResult InvokeUnmarshalled<T0, T1, T2, TResult>(string identifier, T0 arg0, T1 arg1, T2 arg2)
         {
             var result = InternalCalls.InvokeJSUnmarshalled<T0, T1, T2, TResult>(out var exception, identifier, arg0, arg1, arg2);
             return exception != null
                 ? throw new JSException(exception)
                 : result;
         }
-
-        #endregion
     }
 }
diff --git a/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntimeExtensions.cs b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntimeExtensions.cs
new file mode 100644
index 0000000000..4ba4de1266
--- /dev/null
+++ b/src/Components/WebAssembly/JSInterop/src/WebAssemblyJSRuntimeExtensions.cs
@@ -0,0 +1,70 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.JSInterop.WebAssembly
+{
+    /// <summary>
+    /// Extension methods for <see cref="WebAssemblyJSRuntime"/>.
+    /// </summary>
+    public static class WebAssemblyJSRuntimeExtensions
+    {
+        /// <summary>
+        /// Invokes the JavaScript function registered with the specified identifier.
+        /// </summary>
+        /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
+        /// <param name="jsRuntime">The <see cref="WebAssemblyJSRuntime"/>.</param>
+        /// <param name="identifier">The identifier used when registering the target function.</param>
+        /// <returns>The result of the function invocation.</returns>
+        public static TResult InvokeUnmarshalled<TResult>(this WebAssemblyJSRuntime jsRuntime, string identifier)
+        {
+            if (jsRuntime is null)
+            {
+                throw new ArgumentNullException(nameof(jsRuntime));
+            }
+
+            return jsRuntime.InvokeUnmarshalled<object, object, object, TResult>(identifier, null, null, null);
+        }
+
+        /// <summary>
+        /// Invokes the JavaScript function registered with the specified identifier.
+        /// </summary>
+        /// <typeparam name="T0">The type of the first argument.</typeparam>
+        /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
+        /// <param name="jsRuntime">The <see cref="WebAssemblyJSRuntime"/>.</param>
+        /// <param name="identifier">The identifier used when registering the target function.</param>
+        /// <param name="arg0">The first argument.</param>
+        /// <returns>The result of the function invocation.</returns>
+        public static TResult InvokeUnmarshalled<T0, TResult>(this WebAssemblyJSRuntime jsRuntime, string identifier, T0 arg0)
+        {
+            if (jsRuntime is null)
+            {
+                throw new ArgumentNullException(nameof(jsRuntime));
+            }
+
+            return jsRuntime.InvokeUnmarshalled<T0, object, object, TResult>(identifier, arg0, null, null);
+        }
+
+        /// <summary>
+        /// Invokes the JavaScript function registered with the specified identifier.
+        /// </summary>
+        /// <typeparam name="T0">The type of the first argument.</typeparam>
+        /// <typeparam name="T1">The type of the second argument.</typeparam>
+        /// <typeparam name="TResult">The .NET type corresponding to the function's return value type.</typeparam>
+        /// <param name="jsRuntime">The <see cref="WebAssemblyJSRuntime"/>.</param>
+        /// <param name="identifier">The identifier used when registering the target function.</param>
+        /// <param name="arg0">The first argument.</param>
+        /// <param name="arg1">The second argument.</param>
+        /// <returns>The result of the function invocation.</returns>
+        public static TResult InvokeUnmarshalled<T0, T1, TResult>(this WebAssemblyJSRuntime jsRuntime, string identifier, T0 arg0, T1 arg1)
+        {
+            if (jsRuntime is null)
+            {
+                throw new ArgumentNullException(nameof(jsRuntime));
+            }
+
+            return jsRuntime.InvokeUnmarshalled<T0, T1, object, TResult>(identifier, arg0, arg1, null);
+        }
+    }
+}
diff --git a/src/Components/WebAssembly/WebAssembly.Authentication/test/WebAssemblyAuthenticationServiceCollectionExtensionsTests.cs b/src/Components/WebAssembly/WebAssembly.Authentication/test/WebAssemblyAuthenticationServiceCollectionExtensionsTests.cs
index b649cc5e2c..b23090b1c2 100644
--- a/src/Components/WebAssembly/WebAssembly.Authentication/test/WebAssemblyAuthenticationServiceCollectionExtensionsTests.cs
+++ b/src/Components/WebAssembly/WebAssembly.Authentication/test/WebAssemblyAuthenticationServiceCollectionExtensionsTests.cs
@@ -6,6 +6,8 @@ using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
+using Microsoft.JSInterop.WebAssembly;
+using Moq;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
@@ -15,7 +17,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
         [Fact]
         public void CanResolve_AccessTokenProvider()
         {
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(GetJSRuntime());
             builder.Services.AddApiAuthorization();
             var host = builder.Build();
 
@@ -25,7 +27,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
         [Fact]
         public void CanResolve_IRemoteAuthenticationService()
         {
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(GetJSRuntime());
             builder.Services.AddApiAuthorization();
             var host = builder.Build();
 
@@ -35,7 +37,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
         [Fact]
         public void ApiAuthorizationOptions_ConfigurationDefaultsGetApplied()
         {
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(GetJSRuntime());
             builder.Services.AddApiAuthorization();
             var host = builder.Build();
 
@@ -69,7 +71,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
         [Fact]
         public void ApiAuthorizationOptions_DefaultsCanBeOverriden()
         {
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(GetJSRuntime());
             builder.Services.AddApiAuthorization(options =>
             {
                 options.AuthenticationPaths = new RemoteAuthenticationApplicationPathsOptions
@@ -129,7 +131,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
         [Fact]
         public void OidcOptions_ConfigurationDefaultsGetApplied()
         {
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(GetJSRuntime());
             builder.Services.Replace(ServiceDescriptor.Singleton<NavigationManager, TestNavigationManager>());
             builder.Services.AddOidcAuthentication(options => { });
             var host = builder.Build();
@@ -167,7 +169,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
         [Fact]
         public void OidcOptions_DefaultsCanBeOverriden()
         {
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(GetJSRuntime());
             builder.Services.AddOidcAuthentication(options =>
             {
                 options.AuthenticationPaths = new RemoteAuthenticationApplicationPathsOptions
@@ -242,5 +244,19 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Authentication
 
             protected override void NavigateToCore(string uri, bool forceLoad) => throw new System.NotImplementedException();
         }
+
+        private WebAssemblyJSRuntime GetJSRuntime(string environment = "Production")
+        {
+            var jsRuntime = new Mock<WebAssemblyJSRuntime>();
+            jsRuntime.Setup(j => j.InvokeUnmarshalled<object, object, object, string>("Blazor._internal.getApplicationEnvironment", null, null, null))
+                .Returns(environment)
+                .Verifiable();
+
+            jsRuntime.Setup(j => j.InvokeUnmarshalled<string, object, object, byte[]>("Blazor._internal.getConfig", It.IsAny<string>(), null, null))
+                .Returns((byte[])null)
+                .Verifiable();
+
+            return jsRuntime.Object;
+        }
     }
 }
diff --git a/src/Components/WebAssembly/WebAssembly/src/Hosting/WebAssemblyHostBuilder.cs b/src/Components/WebAssembly/WebAssembly/src/Hosting/WebAssemblyHostBuilder.cs
index f7113d4041..02017004bf 100644
--- a/src/Components/WebAssembly/WebAssembly/src/Hosting/WebAssemblyHostBuilder.cs
+++ b/src/Components/WebAssembly/WebAssembly/src/Hosting/WebAssemblyHostBuilder.cs
@@ -5,7 +5,6 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
 using Microsoft.AspNetCore.Components.Routing;
 using Microsoft.AspNetCore.Components.WebAssembly.Services;
 using Microsoft.Extensions.Configuration;
@@ -14,6 +13,7 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Logging;
 using Microsoft.JSInterop;
+using Microsoft.JSInterop.WebAssembly;
 
 namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
 {
@@ -35,7 +35,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
             // We don't use the args for anything right now, but we want to accept them
             // here so that it shows up this way in the project templates.
             args ??= Array.Empty<string>();
-            var builder = new WebAssemblyHostBuilder();
+            var builder = new WebAssemblyHostBuilder(DefaultWebAssemblyJSRuntime.Instance);
 
             // Right now we don't have conventions or behaviors that are specific to this method
             // however, making this the default for the template allows us to add things like that
@@ -47,7 +47,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         /// <summary>
         /// Creates an instance of <see cref="WebAssemblyHostBuilder"/> with the minimal configuration.
         /// </summary>
-        private WebAssemblyHostBuilder()
+        internal WebAssemblyHostBuilder(WebAssemblyJSRuntime jsRuntime)
         {
             // Private right now because we don't have much reason to expose it. This can be exposed
             // in the future if we want to give people a choice between CreateDefault and something
@@ -58,25 +58,20 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
 
             InitializeDefaultServices();
 
+            var hostEnvironment = InitializeEnvironment(jsRuntime);
+
             _createServiceProvider = () =>
             {
-                return Services.BuildServiceProvider();
+                return Services.BuildServiceProvider(validateScopes: hostEnvironment.Environment == "Development");
             };
-
-            InitializeEnvironment();
         }
 
-        private void InitializeEnvironment()
+        private WebAssemblyHostEnvironment InitializeEnvironment(WebAssemblyJSRuntime jsRuntime)
         {
-            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Create("WEBASSEMBLY")))
-            {
-                // The remainder of this method relies on the ability to make .NET WebAssembly-specific JSInterop calls.
-                // Note that this short-circuit exists as a way for unit tests running in .NET Core without JSInterop to run.
-                return;
-            }
+            var applicationEnvironment = jsRuntime.InvokeUnmarshalled<string>("Blazor._internal.getApplicationEnvironment");
+            var hostEnvironment = new WebAssemblyHostEnvironment(applicationEnvironment);
 
-            var applicationEnvironment = DefaultWebAssemblyJSRuntime.Instance.InvokeUnmarshalled<string>("Blazor._internal.getApplicationEnvironment");
-            Services.AddSingleton<IWebAssemblyHostEnvironment>(new WebAssemblyHostEnvironment(applicationEnvironment));
+            Services.AddSingleton<IWebAssemblyHostEnvironment>(hostEnvironment);
 
             var configFiles = new[]
             {
@@ -86,7 +81,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
 
             foreach (var configFile in configFiles)
             {
-                var appSettingsJson = DefaultWebAssemblyJSRuntime.Instance.InvokeUnmarshalled<string, byte[]>(
+                var appSettingsJson = jsRuntime.InvokeUnmarshalled<string, byte[]>(
                     "Blazor._internal.getConfig",
                     configFile);
 
@@ -97,6 +92,8 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
                     Configuration.Add<JsonStreamConfigurationSource>(s => s.Stream = new MemoryStream(appSettingsJson));
                 }
             }
+
+            return hostEnvironment;
         }
 
         /// <summary>
diff --git a/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.csproj b/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.csproj
index b2e8302cc4..c543a7a11b 100644
--- a/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.csproj
+++ b/src/Components/WebAssembly/WebAssembly/src/Microsoft.AspNetCore.Components.WebAssembly.csproj
@@ -23,6 +23,7 @@
 
   <ItemGroup>
     <InternalsVisibleTo Include="Microsoft.AspNetCore.Components.WebAssembly.Tests" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Components.WebAssembly.Authentication.Tests" />
     <InternalsVisibleTo Include="BasicTestApp" />
   </ItemGroup>
 
diff --git a/src/Components/WebAssembly/WebAssembly/src/Rendering/WebAssemblyRenderer.cs b/src/Components/WebAssembly/WebAssembly/src/Rendering/WebAssemblyRenderer.cs
index 8615b05847..d9e81acf15 100644
--- a/src/Components/WebAssembly/WebAssembly/src/Rendering/WebAssemblyRenderer.cs
+++ b/src/Components/WebAssembly/WebAssembly/src/Rendering/WebAssemblyRenderer.cs
@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Components.RenderTree;
 using Microsoft.AspNetCore.Components.WebAssembly.Services;
 using Microsoft.Extensions.Logging;
+using Microsoft.JSInterop.WebAssembly;
 
 namespace Microsoft.AspNetCore.Components.WebAssembly.Rendering
 {
diff --git a/src/Components/WebAssembly/WebAssembly/test/Hosting/TestWebAssemblyJSRuntime.cs b/src/Components/WebAssembly/WebAssembly/test/Hosting/TestWebAssemblyJSRuntime.cs
new file mode 100644
index 0000000000..74a251a28e
--- /dev/null
+++ b/src/Components/WebAssembly/WebAssembly/test/Hosting/TestWebAssemblyJSRuntime.cs
@@ -0,0 +1,25 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.JSInterop.WebAssembly;
+using Moq;
+
+namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
+{
+    public class TestWebAssemblyJSRuntime
+    {
+        public static WebAssemblyJSRuntime Create(string environment = "Production")
+        {
+            var jsRuntime = new Mock<WebAssemblyJSRuntime>();
+            jsRuntime.Setup(j => j.InvokeUnmarshalled<object, object, object, string>("Blazor._internal.getApplicationEnvironment", null, null, null))
+                .Returns(environment)
+                .Verifiable();
+
+            jsRuntime.Setup(j => j.InvokeUnmarshalled<string, object, object, byte[]>("Blazor._internal.getConfig", It.IsAny<string>(), null, null))
+                .Returns((byte[])null)
+                .Verifiable();
+
+            return jsRuntime.Object;
+        }
+    }
+}
diff --git a/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostBuilderTest.cs b/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostBuilderTest.cs
index 5acc214437..b6378dca9a 100644
--- a/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostBuilderTest.cs
+++ b/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostBuilderTest.cs
@@ -3,14 +3,14 @@
 
 using System;
 using System.Collections.Generic;
-using System.Net.Http;
 using System.Text;
-using Microsoft.AspNetCore.Components;
 using Microsoft.AspNetCore.Components.Routing;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.JSInterop;
+using Microsoft.JSInterop.WebAssembly;
+using Moq;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
@@ -21,7 +21,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public void Build_AllowsConfiguringConfiguration()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
 
             builder.Configuration.AddInMemoryCollection(new[]
             {
@@ -39,7 +39,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public void Build_AllowsConfiguringServices()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
 
             // This test also verifies that we create a scope.
             builder.Services.AddScoped<StringBuilder>();
@@ -55,7 +55,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public void Build_AllowsConfiguringContainer()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
 
             builder.Services.AddScoped<StringBuilder>();
             var factory = new MyFakeServiceProviderFactory();
@@ -73,7 +73,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public void Build_AllowsConfiguringContainer_WithDelegate()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
 
             builder.Services.AddScoped<StringBuilder>();
 
@@ -92,6 +92,46 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
             Assert.NotNull(host.Services.GetRequiredService<List<string>>());
         }
 
+        [Fact]
+        public void Build_InDevelopment_ConfiguresWithServiceProviderWithScopeValidation()
+        {
+            // Arrange
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create(environment: "Development"));
+
+            builder.Services.AddScoped<StringBuilder>();
+            builder.Services.AddSingleton<TestServiceThatTakesStringBuilder>();
+
+            // Act
+            var host = builder.Build();
+
+            // Assert
+            Assert.NotNull(host.Services.GetRequiredService<StringBuilder>());
+            Assert.Throws<InvalidOperationException>(() => host.Services.GetRequiredService<TestServiceThatTakesStringBuilder>());
+        }
+
+        [Fact]
+        public void Build_InProduction_ConfiguresWithServiceProviderWithScopeValidation()
+        {
+            // Arrange
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
+
+            builder.Services.AddScoped<StringBuilder>();
+            builder.Services.AddSingleton<TestServiceThatTakesStringBuilder>();
+
+            // Act
+            var host = builder.Build();
+
+            // Assert
+            Assert.NotNull(host.Services.GetRequiredService<StringBuilder>());
+            Assert.NotNull(host.Services.GetRequiredService<TestServiceThatTakesStringBuilder>());
+        }
+
+        private class TestServiceThatTakesStringBuilder
+        {
+            public TestServiceThatTakesStringBuilder(StringBuilder builder) { }
+        }
+
+
         private class MyFakeDIBuilderThing
         {
             public MyFakeDIBuilderThing(IServiceCollection serviceCollection)
@@ -125,7 +165,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public void Build_AddsConfigurationToServices()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
 
             builder.Configuration.AddInMemoryCollection(new[]
             {
@@ -151,6 +191,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
                     typeof(INavigationInterception),
                     typeof(ILoggerFactory),
                     typeof(ILogger<>),
+                    typeof(IWebAssemblyHostEnvironment),
                 };
             }
         }
@@ -159,7 +200,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public void Constructor_AddsDefaultServices()
         {
             // Arrange & Act
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
 
             // Assert
             Assert.Equal(DefaultServiceTypes.Count, builder.Services.Count);
diff --git a/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostTest.cs b/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostTest.cs
index 9fcdb7b8ec..a67363ba5c 100644
--- a/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostTest.cs
+++ b/src/Components/WebAssembly/WebAssembly/test/Hosting/WebAssemblyHostTest.cs
@@ -18,7 +18,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public async Task RunAsync_CanExitBasedOnCancellationToken()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
             var host = builder.Build();
 
             var cts = new CancellationTokenSource();
@@ -36,7 +36,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public async Task RunAsync_CallingTwiceCausesException()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
             var host = builder.Build();
 
             var cts = new CancellationTokenSource();
@@ -56,7 +56,7 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Hosting
         public async Task DisposeAsync_CanDisposeAfterCallingRunAsync()
         {
             // Arrange
-            var builder = WebAssemblyHostBuilder.CreateDefault();
+            var builder = new WebAssemblyHostBuilder(TestWebAssemblyJSRuntime.Create());
             builder.Services.AddSingleton<DisposableService>();
             var host = builder.Build();