diff --git a/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/DynamicServiceProviderEngine.cs b/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/DynamicServiceProviderEngine.cs
index ee124f31be8eff..0237e8ad096b74 100644
--- a/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/DynamicServiceProviderEngine.cs
+++ b/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/DynamicServiceProviderEngine.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Diagnostics;
 using System.Threading;
 
 namespace Microsoft.Extensions.DependencyInjection.ServiceLookup
@@ -37,6 +38,8 @@ public override Func<ServiceProviderEngineScope, object> RealizeService(ServiceC
                         catch (Exception ex)
                         {
                             DependencyInjectionEventSource.Log.ServiceRealizationFailed(ex);
+
+                            Debug.Fail($"We should never get exceptions from the background compilation.{Environment.NewLine}{ex}");
                         }
                     },
                     null);
diff --git a/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceProvider.cs b/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceProvider.cs
index b93a11d9566192..afe118acf79093 100644
--- a/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceProvider.cs
+++ b/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceProvider.cs
@@ -32,11 +32,12 @@ public sealed class ServiceProvider : IServiceProvider, IDisposable, IAsyncDispo
 
         internal ServiceProvider(IEnumerable<ServiceDescriptor> serviceDescriptors, ServiceProviderOptions options)
         {
+            // note that Root needs to be set before calling GetEngine(), because the engine may need to access Root
+            Root = new ServiceProviderEngineScope(this, isRootScope: true);
             _engine = GetEngine();
             _createServiceAccessor = CreateServiceAccessor;
             _realizedServices = new ConcurrentDictionary<Type, Func<ServiceProviderEngineScope, object>>();
 
-            Root = new ServiceProviderEngineScope(this, isRootScope: true);
             CallSiteFactory = new CallSiteFactory(serviceDescriptors);
             // The list of built in services that aren't part of the list of service descriptors
             // keep this in sync with CallSiteFactory.IsService