diff --git a/Source/timeout/timeout.Domain.Tests/timeout.Domain.Tests.csproj b/Source/timeout/timeout.Domain.Tests/timeout.Domain.Tests.csproj
index bae269f..ad21c3b 100644
--- a/Source/timeout/timeout.Domain.Tests/timeout.Domain.Tests.csproj
+++ b/Source/timeout/timeout.Domain.Tests/timeout.Domain.Tests.csproj
@@ -9,7 +9,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0" />
-    <PackageReference Include="NUnit" Version="3.13.3" />
+    <PackageReference Include="NUnit" Version="4.5.1" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.4.2" />
   </ItemGroup>