diff --git a/Abjad Calculator.Tests/Abjad Calculator.Tests.csproj b/Abjad Calculator.Tests/Abjad Calculator.Tests.csproj
index f6746ba..f935d01 100644
--- a/Abjad Calculator.Tests/Abjad Calculator.Tests.csproj	
+++ b/Abjad Calculator.Tests/Abjad Calculator.Tests.csproj	
@@ -11,7 +11,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageReference Include="xunit" Version="2.9.2" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="4.0.0" />
   </ItemGroup>
 
   <ItemGroup>