diff --git a/test/ApiMark.Cpp.Tests/ApiMark.Cpp.Tests.csproj b/test/ApiMark.Cpp.Tests/ApiMark.Cpp.Tests.csproj
index 57b6c7b..b55bc39 100644
--- a/test/ApiMark.Cpp.Tests/ApiMark.Cpp.Tests.csproj
+++ b/test/ApiMark.Cpp.Tests/ApiMark.Cpp.Tests.csproj
@@ -7,6 +7,7 @@
     <IsPackable>false</IsPackable>
     <AssemblyName>ApiMark.Cpp.Tests</AssemblyName>
     <RootNamespace>ApiMark.Cpp.Tests</RootNamespace>
+    <TestTfmsInParallel>false</TestTfmsInParallel>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="coverlet.collector" Version="6.0.4">
diff --git a/test/ApiMark.DotNet.Tests/ApiMark.DotNet.Tests.csproj b/test/ApiMark.DotNet.Tests/ApiMark.DotNet.Tests.csproj
index dabc6f6..402b010 100644
--- a/test/ApiMark.DotNet.Tests/ApiMark.DotNet.Tests.csproj
+++ b/test/ApiMark.DotNet.Tests/ApiMark.DotNet.Tests.csproj
@@ -7,6 +7,7 @@
     <IsPackable>false</IsPackable>
     <AssemblyName>ApiMark.DotNet.Tests</AssemblyName>
     <RootNamespace>ApiMark.DotNet.Tests</RootNamespace>
+    <TestTfmsInParallel>false</TestTfmsInParallel>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="coverlet.collector" Version="6.0.4">