diff --git a/test/Spectre.Console.Tests/Spectre.Console.Tests.csproj b/test/Spectre.Console.Tests/Spectre.Console.Tests.csproj
index 7b8edd7..a7f7d21 100644
--- a/test/Spectre.Console.Tests/Spectre.Console.Tests.csproj
+++ b/test/Spectre.Console.Tests/Spectre.Console.Tests.csproj
@@ -1,7 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net5.0</TargetFrameworks>
+    <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">net5.0;net48</TargetFrameworks>
+    <TargetFramework Condition="!$([MSBuild]::IsOSPlatform('Windows'))">net5.0</TargetFramework>
+    <LangVersion>9.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
@@ -17,10 +19,12 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="IsExternalInit" Version="1.0.1" PrivateAssets="all" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing.XUnit" Version="1.1.0" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing.XUnit" Version="1.1.0" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="2.6.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+    <PackageReference Include="Nullable" Version="1.3.0" PrivateAssets="all" />
     <PackageReference Include="Shouldly" Version="4.0.3" />
     <PackageReference Include="Spectre.Verify.Extensions" Version="0.3.0" />
     <PackageReference Include="Verify.Xunit" Version="9.0.0-beta.1" />
diff --git a/test/Spectre.Console.Tests/VerifyConfiguration.cs b/test/Spectre.Console.Tests/VerifyConfiguration.cs
index 93c0d03..cda1898 100644
--- a/test/Spectre.Console.Tests/VerifyConfiguration.cs
+++ b/test/Spectre.Console.Tests/VerifyConfiguration.cs
@@ -12,4 +12,14 @@ namespace Spectre.Console.Tests
             VerifierSettings.DerivePathInfo(Expectations.Initialize);
         }
     }
-}
\ No newline at end of file
+}
+
+#if !NET5_0_OR_GREATER
+namespace System.Runtime.CompilerServices
+{
+    [AttributeUsage(AttributeTargets.Method, Inherited = false)]
+    public sealed class ModuleInitializerAttribute : Attribute
+    {
+    }
+}
+#endif