diff --git a/ApiDoctor.DocumentationGeneration.UnitTests/ApiDoctor.DocumentationGeneration.UnitTests.csproj b/ApiDoctor.DocumentationGeneration.UnitTests/ApiDoctor.DocumentationGeneration.UnitTests.csproj
index 10ee6cad..7c88aff0 100644
--- a/ApiDoctor.DocumentationGeneration.UnitTests/ApiDoctor.DocumentationGeneration.UnitTests.csproj
+++ b/ApiDoctor.DocumentationGeneration.UnitTests/ApiDoctor.DocumentationGeneration.UnitTests.csproj
@@ -24,7 +24,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit" Version="4.0.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
   </ItemGroup>
   <ItemGroup>
diff --git a/ApiDoctor.Validation.UnitTests/ApiDoctor.Validation.UnitTests.csproj b/ApiDoctor.Validation.UnitTests/ApiDoctor.Validation.UnitTests.csproj
index 3f080e95..8c25a6ca 100644
--- a/ApiDoctor.Validation.UnitTests/ApiDoctor.Validation.UnitTests.csproj
+++ b/ApiDoctor.Validation.UnitTests/ApiDoctor.Validation.UnitTests.csproj
@@ -41,7 +41,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit" Version="4.0.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
     <PackageReference Include="System.ComponentModel.Composition" Version="8.0.0" />
     <PackageReference Include="System.Data.DataSetExtensions" Version="4.5.0" />