diff --git a/src/Stravaig.FamilyTree.Standardiser.UnitTests/Stravaig.FamilyTree.Standardiser.UnitTests.csproj b/src/Stravaig.FamilyTree.Standardiser.UnitTests/Stravaig.FamilyTree.Standardiser.UnitTests.csproj
index 9b265cd..4a4c9c1 100644
--- a/src/Stravaig.FamilyTree.Standardiser.UnitTests/Stravaig.FamilyTree.Standardiser.UnitTests.csproj
+++ b/src/Stravaig.FamilyTree.Standardiser.UnitTests/Stravaig.FamilyTree.Standardiser.UnitTests.csproj
@@ -7,7 +7,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="nunit" Version="3.13.0" />
+        <PackageReference Include="nunit" Version="3.13.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
         <PackageReference Include="Shouldly" Version="4.0.3" />
diff --git a/src/Stravaig.FamilyTreeGenerator.Tests/Stravaig.FamilyTreeGenerator.Tests.csproj b/src/Stravaig.FamilyTreeGenerator.Tests/Stravaig.FamilyTreeGenerator.Tests.csproj
index 3247066..9492b01 100644
--- a/src/Stravaig.FamilyTreeGenerator.Tests/Stravaig.FamilyTreeGenerator.Tests.csproj
+++ b/src/Stravaig.FamilyTreeGenerator.Tests/Stravaig.FamilyTreeGenerator.Tests.csproj
@@ -7,7 +7,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="nunit" Version="3.13.0" />
+        <PackageReference Include="nunit" Version="3.13.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
     </ItemGroup>
diff --git a/src/Stravaig.Gedcom.UnitTests/Stravaig.Gedcom.UnitTests.csproj b/src/Stravaig.Gedcom.UnitTests/Stravaig.Gedcom.UnitTests.csproj
index d48e94b..692a049 100644
--- a/src/Stravaig.Gedcom.UnitTests/Stravaig.Gedcom.UnitTests.csproj
+++ b/src/Stravaig.Gedcom.UnitTests/Stravaig.Gedcom.UnitTests.csproj
@@ -8,7 +8,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="nunit" Version="3.13.0" />
+        <PackageReference Include="nunit" Version="3.13.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
         <PackageReference Include="Shouldly" Version="4.0.3" />