diff --git a/src/OpenIddict.Mvc/OpenIddictModelBinder.cs b/src/OpenIddict.Mvc/OpenIddictModelBinder.cs
index 9a716717..a05f33e6 100644
--- a/src/OpenIddict.Mvc/OpenIddictModelBinder.cs
+++ b/src/OpenIddict.Mvc/OpenIddictModelBinder.cs
@@ -2,9 +2,9 @@
 using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Primitives;
 using JetBrains.Annotations;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace OpenIddict.Mvc
 {
diff --git a/src/OpenIddict/OpenIddictExtensions.cs b/src/OpenIddict/OpenIddictExtensions.cs
index 87bdefb3..9960ae52 100644
--- a/src/OpenIddict/OpenIddictExtensions.cs
+++ b/src/OpenIddict/OpenIddictExtensions.cs
@@ -17,13 +17,12 @@ using JetBrains.Annotations;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.DataProtection;
 using Microsoft.AspNetCore.Http;
-using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
 using Microsoft.IdentityModel.Tokens;
 using OpenIddict;
 
-namespace Microsoft.AspNetCore.Builder
+namespace Microsoft.Extensions.DependencyInjection
 {
     public static class OpenIddictExtensions
     {
diff --git a/test/OpenIddict.Tests/OpenIddictProviderTests.Authentication.cs b/test/OpenIddict.Tests/OpenIddictProviderTests.Authentication.cs
index 2fe995d0..d84d9972 100644
--- a/test/OpenIddict.Tests/OpenIddictProviderTests.Authentication.cs
+++ b/test/OpenIddict.Tests/OpenIddictProviderTests.Authentication.cs
@@ -1,11 +1,8 @@
-using System;
-using System.IO;
-using System.Linq;
+using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Client;
 using AspNet.Security.OpenIdConnect.Primitives;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.Caching.Distributed;
 using Microsoft.Extensions.DependencyInjection;
 using Moq;
diff --git a/test/OpenIddict.Tests/OpenIddictProviderTests.Discovery.cs b/test/OpenIddict.Tests/OpenIddictProviderTests.Discovery.cs
index 962bf052..1b3e3d81 100644
--- a/test/OpenIddict.Tests/OpenIddictProviderTests.Discovery.cs
+++ b/test/OpenIddict.Tests/OpenIddictProviderTests.Discovery.cs
@@ -1,11 +1,10 @@
-using System.Linq;
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Client;
 using AspNet.Security.OpenIdConnect.Primitives;
 using Microsoft.AspNetCore.Authentication.Cookies;
 using Microsoft.AspNetCore.Authentication.Facebook;
 using Microsoft.AspNetCore.Authentication.Google;
-using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
 using Newtonsoft.Json.Linq;
 using OpenIddict.Core;
 using Xunit;
diff --git a/test/OpenIddict.Tests/OpenIddictProviderTests.Exchange.cs b/test/OpenIddict.Tests/OpenIddictProviderTests.Exchange.cs
index 6065a6b0..709f54e0 100644
--- a/test/OpenIddict.Tests/OpenIddictProviderTests.Exchange.cs
+++ b/test/OpenIddict.Tests/OpenIddictProviderTests.Exchange.cs
@@ -1,5 +1,4 @@
-using System.Collections.Generic;
-using System.Security.Claims;
+using System.Security.Claims;
 using System.Threading;
 using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Client;
@@ -7,7 +6,6 @@ using AspNet.Security.OpenIdConnect.Extensions;
 using AspNet.Security.OpenIdConnect.Primitives;
 using AspNet.Security.OpenIdConnect.Server;
 using Microsoft.AspNetCore.Authentication;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Moq;
diff --git a/test/OpenIddict.Tests/OpenIddictProviderTests.Introspection.cs b/test/OpenIddict.Tests/OpenIddictProviderTests.Introspection.cs
index 69f6165c..ab4275f3 100644
--- a/test/OpenIddict.Tests/OpenIddictProviderTests.Introspection.cs
+++ b/test/OpenIddict.Tests/OpenIddictProviderTests.Introspection.cs
@@ -1,5 +1,4 @@
-using System.Linq;
-using System.Security.Claims;
+using System.Security.Claims;
 using System.Threading;
 using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Client;
@@ -7,7 +6,6 @@ using AspNet.Security.OpenIdConnect.Extensions;
 using AspNet.Security.OpenIdConnect.Primitives;
 using AspNet.Security.OpenIdConnect.Server;
 using Microsoft.AspNetCore.Authentication;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Moq;
diff --git a/test/OpenIddict.Tests/OpenIddictProviderTests.Revocation.cs b/test/OpenIddict.Tests/OpenIddictProviderTests.Revocation.cs
index 40fdefaf..f062cff0 100644
--- a/test/OpenIddict.Tests/OpenIddictProviderTests.Revocation.cs
+++ b/test/OpenIddict.Tests/OpenIddictProviderTests.Revocation.cs
@@ -8,7 +8,6 @@ using AspNet.Security.OpenIdConnect.Extensions;
 using AspNet.Security.OpenIdConnect.Primitives;
 using AspNet.Security.OpenIdConnect.Server;
 using Microsoft.AspNetCore.Authentication;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.IdentityModel.Tokens;
 using Moq;
diff --git a/test/OpenIddict.Tests/OpenIddictProviderTests.Serialization.cs b/test/OpenIddict.Tests/OpenIddictProviderTests.Serialization.cs
index fba55324..fe10bb4f 100644
--- a/test/OpenIddict.Tests/OpenIddictProviderTests.Serialization.cs
+++ b/test/OpenIddict.Tests/OpenIddictProviderTests.Serialization.cs
@@ -1,12 +1,9 @@
 using System;
-using System.Collections;
-using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Client;
 using AspNet.Security.OpenIdConnect.Primitives;
 using Microsoft.AspNetCore.Authentication;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Moq;
diff --git a/test/OpenIddict.Tests/OpenIddictProviderTests.Session.cs b/test/OpenIddict.Tests/OpenIddictProviderTests.Session.cs
index e6dbc6a1..d610c289 100644
--- a/test/OpenIddict.Tests/OpenIddictProviderTests.Session.cs
+++ b/test/OpenIddict.Tests/OpenIddictProviderTests.Session.cs
@@ -1,14 +1,11 @@
-using System.Linq;
-using System.Threading;
+using System.Threading;
 using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Client;
 using AspNet.Security.OpenIdConnect.Primitives;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.Caching.Distributed;
 using Microsoft.Extensions.DependencyInjection;
 using Moq;
 using OpenIddict.Core;
-using OpenIddict.Models;
 using Xunit;
 
 namespace OpenIddict.Tests