diff --git a/README.md b/README.md
index aaa7af7e..65ea8a7a 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ This repository contains samples demonstrating **how to use [OpenIddict](https:/
   - [Sorgan](samples/Sorgan): console, Windows Forms, Windows Presentation Foundation and Blazor Hybrid clients using GitHub for user authentication.
 
 ## OWIN/ASP.NET 4.8 samples
-  - [Fornax](samples/Fornax): authorization code flow demo using ASP.NET Web Forms 4.8 and OWIN/Katana, with a .NET Framework 4.8 console acting as the client.
+  - [Fornax](samples/Fornax): authorization code flow demo using ASP.NET Web Forms 4.8 and OWIN/Katana, with a .NET console acting as the client.
   - [Mortis](samples/Mortis): authorization code flow demo using ASP.NET MVC 5.2 and ASP.NET Web API 2.2, with an ASP.NET MVC 5.2 application acting as the client.
   - [Kalarba](samples/Kalarba): resource owner password credentials demo using OWIN/Katana, ASP.NET Web API 2.2 and the OpenIddict degraded mode.
 
diff --git a/samples/Dantooine/Dantooine.Api/Program.cs b/samples/Dantooine/Dantooine.Api/Program.cs
index 0f6e119b..88362212 100644
--- a/samples/Dantooine/Dantooine.Api/Program.cs
+++ b/samples/Dantooine/Dantooine.Api/Program.cs
@@ -1,5 +1,4 @@
 using System.Security.Cryptography;
-using Microsoft.AspNetCore.Authorization;
 using Microsoft.IdentityModel.Tokens;
 using OpenIddict.Validation.AspNetCore;
 
diff --git a/samples/Fornax/Fornax.Client/Fornax.Client.csproj b/samples/Fornax/Fornax.Client/Fornax.Client.csproj
index 661dbaeb..c04e7c00 100644
--- a/samples/Fornax/Fornax.Client/Fornax.Client.csproj
+++ b/samples/Fornax/Fornax.Client/Fornax.Client.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>$(NetFrameworkTargetFramework)</TargetFramework>
+    <TargetFramework>$(NetCoreTargetFramework)</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/samples/Kalarba/Kalarba.Client/Kalarba.Client.csproj b/samples/Kalarba/Kalarba.Client/Kalarba.Client.csproj
index bf19d3b6..66420665 100644
--- a/samples/Kalarba/Kalarba.Client/Kalarba.Client.csproj
+++ b/samples/Kalarba/Kalarba.Client/Kalarba.Client.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>$(NetFrameworkTargetFramework)</TargetFramework>
+    <TargetFramework>$(NetCoreTargetFramework)</TargetFramework>
     <OutputType>Exe</OutputType>
   </PropertyGroup>
 
diff --git a/samples/Kalarba/Kalarba.Client/Program.cs b/samples/Kalarba/Kalarba.Client/Program.cs
index f562a13b..d8cd5d78 100644
--- a/samples/Kalarba/Kalarba.Client/Program.cs
+++ b/samples/Kalarba/Kalarba.Client/Program.cs
@@ -1,5 +1,4 @@
-using System.Net.Http;
-using System.Net.Http.Headers;
+using System.Net.Http.Headers;
 using Microsoft.Extensions.DependencyInjection;
 using OpenIddict.Client;
 
diff --git a/samples/Mimban/Mimban.Server/Program.cs b/samples/Mimban/Mimban.Server/Program.cs
index 7c6ee1ce..146499e1 100644
--- a/samples/Mimban/Mimban.Server/Program.cs
+++ b/samples/Mimban/Mimban.Server/Program.cs
@@ -1,13 +1,11 @@
 using System.Security.Claims;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authentication.Cookies;
-using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Http.Extensions;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.IdentityModel.Tokens;
 using OpenIddict.Abstractions;
 using OpenIddict.Server.AspNetCore;
-using OpenIddict.Validation.AspNetCore;
 using Quartz;
 using static OpenIddict.Abstractions.OpenIddictConstants;
 using static OpenIddict.Client.WebIntegration.OpenIddictClientWebIntegrationConstants;
diff --git a/samples/Zirku/Zirku.Api1/Program.cs b/samples/Zirku/Zirku.Api1/Program.cs
index 4cfc97a4..7d201241 100644
--- a/samples/Zirku/Zirku.Api1/Program.cs
+++ b/samples/Zirku/Zirku.Api1/Program.cs
@@ -2,7 +2,6 @@
 using System.Security.Claims;
 using System.Security.Cryptography;
 using System.Security.Cryptography.X509Certificates;
-using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Https;
 using Microsoft.IdentityModel.Tokens;
diff --git a/samples/Zirku/Zirku.Api2/Program.cs b/samples/Zirku/Zirku.Api2/Program.cs
index 86e86ad9..c0d8a8b9 100644
--- a/samples/Zirku/Zirku.Api2/Program.cs
+++ b/samples/Zirku/Zirku.Api2/Program.cs
@@ -1,7 +1,6 @@
 using System.Net.Security;
 using System.Security.Claims;
 using System.Security.Cryptography.X509Certificates;
-using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Https;
 using Microsoft.IdentityModel.Tokens;