diff --git a/src/TestHelper/TestHelper.csproj b/src/TestHelper/TestHelper.csproj
index 88359f4c..978b7b6f 100644
--- a/src/TestHelper/TestHelper.csproj
+++ b/src/TestHelper/TestHelper.csproj
@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit" Version="4.5.1" />
     <PackageReference Include="NUnit.Analyzers" Version="4.6.0" />
   </ItemGroup>
 
diff --git a/src/TimeoutMigrationTool.Tests/TimeoutMigrationTool.Tests.csproj b/src/TimeoutMigrationTool.Tests/TimeoutMigrationTool.Tests.csproj
index c3a683cc..394501f9 100644
--- a/src/TimeoutMigrationTool.Tests/TimeoutMigrationTool.Tests.csproj
+++ b/src/TimeoutMigrationTool.Tests/TimeoutMigrationTool.Tests.csproj
@@ -11,7 +11,7 @@
   <ItemGroup>
     <PackageReference Include="GitHubActionsTestLogger" Version="3.0.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
-    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit" Version="4.5.1" />
     <PackageReference Include="NUnit.Analyzers" Version="4.6.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="6.1.0" />
   </ItemGroup>