diff --git a/Source/timeout/timeout.Domain.Tests/timeout.Domain.Tests.csproj b/Source/timeout/timeout.Domain.Tests/timeout.Domain.Tests.csproj
index 0d27f40..2cab2a8 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="18.4.0" />
-    <PackageReference Include="NUnit" Version="3.13.3" />
+    <PackageReference Include="NUnit" Version="4.5.1" />
     <PackageReference Include="NUnit3TestAdapter" Version="6.2.0" />
   </ItemGroup>