diff --git a/src/Tests/Finos.Fdc3.AppDirectory.Tests/Finos.Fdc3.AppDirectory.Tests.csproj b/src/Tests/Finos.Fdc3.AppDirectory.Tests/Finos.Fdc3.AppDirectory.Tests.csproj
index bd8bcdb..1d2e8f3 100644
--- a/src/Tests/Finos.Fdc3.AppDirectory.Tests/Finos.Fdc3.AppDirectory.Tests.csproj
+++ b/src/Tests/Finos.Fdc3.AppDirectory.Tests/Finos.Fdc3.AppDirectory.Tests.csproj
@@ -20,7 +20,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0-preview-23577-04" />
-    <PackageReference Include="xunit" Version="2.6.3" />
+    <PackageReference Include="xunit" Version="2.6.6" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
diff --git a/src/Tests/Finos.Fdc3.NewtonsoftJson.Tests/Finos.Fdc3.NewtonsoftJson.Tests.csproj b/src/Tests/Finos.Fdc3.NewtonsoftJson.Tests/Finos.Fdc3.NewtonsoftJson.Tests.csproj
index b12187c..f471175 100644
--- a/src/Tests/Finos.Fdc3.NewtonsoftJson.Tests/Finos.Fdc3.NewtonsoftJson.Tests.csproj
+++ b/src/Tests/Finos.Fdc3.NewtonsoftJson.Tests/Finos.Fdc3.NewtonsoftJson.Tests.csproj
@@ -22,7 +22,7 @@
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0-preview-23577-04" />
         <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
         <PackageReference Include="Newtonsoft.Json.Schema" Version="3.0.14" />
-        <PackageReference Include="xunit" Version="2.6.3" />
+        <PackageReference Include="xunit" Version="2.6.6" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
diff --git a/src/Tests/Finos.Fdc3.Tests/Finos.Fdc3.Tests.csproj b/src/Tests/Finos.Fdc3.Tests/Finos.Fdc3.Tests.csproj
index f108341..f037ea7 100644
--- a/src/Tests/Finos.Fdc3.Tests/Finos.Fdc3.Tests.csproj
+++ b/src/Tests/Finos.Fdc3.Tests/Finos.Fdc3.Tests.csproj
@@ -10,7 +10,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0-preview-23577-04" />
-    <PackageReference Include="xunit" Version="2.6.3" />
+    <PackageReference Include="xunit" Version="2.6.6" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>