diff --git a/Directory.Packages.props b/Directory.Packages.props
index b6ef500e..80ae3a8f 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -9,7 +9,7 @@
          xunit.v3.core.mtp-v1, whose Microsoft.Testing.Platform version is incompatible with
          a directly-referenced/newer Microsoft.Testing.Platform and throws TypeLoadException
          (IDataConsumer) at test-host startup. -->
-    <PackageVersion Include="Microsoft.Testing.Platform" Version="2.4.1" />
+    <PackageVersion Include="Microsoft.Testing.Platform" Version="2.5.1" />
     <!-- Ships Microsoft.Testing.Extensions.MSBuild.dll, the `dotnet test`-via-MTP entry point's own
          runtime dependency. TestingPlatformDotnetTestSupport=true is supposed to auto-add this
          package via the .NET SDK's own targets, but under Central Package Management with no pinned
@@ -22,8 +22,8 @@
          Compono.TUnit.SampleTests had no equivalent explicit, CPM-pinned reference at all. An
          explicit PackageReference (added to both projects) makes restore resolve it deterministically
          instead of depending on the SDK's own auto-injection timing. -->
-    <PackageVersion Include="Microsoft.Testing.Platform.MSBuild" Version="2.4.1" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.10.1" />
+    <PackageVersion Include="Microsoft.Testing.Platform.MSBuild" Version="2.5.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.11.0" />
     <PackageVersion Include="xunit.v3.mtp-v2" Version="4.0.1" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
     <!-- samples/Compono.Samples.AspNetApi.Tests' own dependency: WebApplicationFactory<T> for the
@@ -58,11 +58,11 @@
          this is the extensibility-authoring layer, matching xunit.v3.extensibility.core's
          own minimal-reference precedent immediately above. A tested-range constraint,
          not a bare unbounded floor or a blanket exact pin, per ADR-0031 Amendment 1. -->
-    <PackageVersion Include="TUnit.Core" Version="[1.72.4, 2.0.0)" />
+    <PackageVersion Include="TUnit.Core" Version="[1.76.0, 2.0.0)" />
     <!-- test/Compono.TUnit.Tests' own dependency - the full TUnit meta-package
          (engine + core + assertions), since that project actually executes as a
          TUnit test run, not just authors against TUnit.Core's extension surface. -->
-    <PackageVersion Include="TUnit" Version="[1.72.4, 2.0.0)" />
+    <PackageVersion Include="TUnit" Version="[1.76.0, 2.0.0)" />
     <!-- Compono.XunitV3.SampleTests' own dependency, same reasoning as Compono.XunitV3/
          Compono.NSubstitute/Compono.Bogus above - never a ProjectReference, and this
          version must match the -p:Version passed to PackToLocalFeed's pack of
@@ -83,7 +83,7 @@
          Compono.MSTest.dll compiled against 3.x cannot implement the ITestDataSource a 4.x test host
          checks for, confirmed by a real FileNotFoundException reproduction during implementation. A
          tested range, not a bare unbounded floor or a blanket exact pin, per ADR-0031 Amendment 1. -->
-    <PackageVersion Include="MSTest.TestFramework" Version="[4.4.1, 5.0.0)" />
+    <PackageVersion Include="MSTest.TestFramework" Version="[4.5.1, 5.0.0)" />
     <!-- test/Compono.MSTest.Tests' own dependency - the full MSTest meta-package (framework +
          adapter + analyzers), since that project actually executes as a real MSTest test run, not
          just authors against MSTest.TestFramework's extension surface. -->
diff --git a/samples/Compono.Samples.AspNetApi.Tests/Compono.Samples.AspNetApi.Tests.csproj b/samples/Compono.Samples.AspNetApi.Tests/Compono.Samples.AspNetApi.Tests.csproj
index 6f2e69a3..ef641763 100644
--- a/samples/Compono.Samples.AspNetApi.Tests/Compono.Samples.AspNetApi.Tests.csproj
+++ b/samples/Compono.Samples.AspNetApi.Tests/Compono.Samples.AspNetApi.Tests.csproj
@@ -30,6 +30,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Testing.Platform" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" VersionOverride="2.5.1" />
     <PackageReference Include="xunit.v3.mtp-v2" />
     <PackageReference Include="NSubstitute" />
     <PackageReference Include="AwesomeAssertions" />
diff --git a/samples/Compono.Samples.BasicUsage/Compono.Samples.BasicUsage.csproj b/samples/Compono.Samples.BasicUsage/Compono.Samples.BasicUsage.csproj
index 312b36a9..b1e39fcd 100644
--- a/samples/Compono.Samples.BasicUsage/Compono.Samples.BasicUsage.csproj
+++ b/samples/Compono.Samples.BasicUsage/Compono.Samples.BasicUsage.csproj
@@ -29,6 +29,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Testing.Platform" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" VersionOverride="2.5.1" />
     <PackageReference Include="xunit.v3.mtp-v2" />
     <PackageReference Include="AwesomeAssertions" />
   </ItemGroup>
diff --git a/test/Compono.Bogus.Tests/Compono.Bogus.Tests.csproj b/test/Compono.Bogus.Tests/Compono.Bogus.Tests.csproj
index 46595246..b4842d0b 100644
--- a/test/Compono.Bogus.Tests/Compono.Bogus.Tests.csproj
+++ b/test/Compono.Bogus.Tests/Compono.Bogus.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" VersionOverride="2.5.1" />
     <ProjectReference Include="..\..\src\Compono.Bogus\Compono.Bogus.csproj" />
     <!-- Coexistence coverage (this plan's own Goal scenario) needs both integration packages
          registered on the same real Composer - see CoexistenceTests.cs. -->
diff --git a/test/Compono.DependencyInjection.Tests/Compono.DependencyInjection.Tests.csproj b/test/Compono.DependencyInjection.Tests/Compono.DependencyInjection.Tests.csproj
index c3f4d34b..f03fbbc8 100644
--- a/test/Compono.DependencyInjection.Tests/Compono.DependencyInjection.Tests.csproj
+++ b/test/Compono.DependencyInjection.Tests/Compono.DependencyInjection.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" VersionOverride="2.5.1" />
     <ProjectReference Include="..\..\src\Compono.DependencyInjection\Compono.DependencyInjection.csproj" />
     <!-- Compono.TestDoubles is a test-project-only dependency here (ADR-0047: the shipped
          Compono.DependencyInjection package itself never references either provider package) - it
diff --git a/test/Compono.Generators.Tests/Compono.Generators.Tests.csproj b/test/Compono.Generators.Tests/Compono.Generators.Tests.csproj
index d343d57e..e30d8ad3 100644
--- a/test/Compono.Generators.Tests/Compono.Generators.Tests.csproj
+++ b/test/Compono.Generators.Tests/Compono.Generators.Tests.csproj
@@ -47,6 +47,7 @@
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net11.0'">
     <PackageReference Include="Basic.Reference.Assemblies.Net110" />
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" VersionOverride="2.5.1" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/test/Compono.Http.Tests/Compono.Http.Tests.csproj b/test/Compono.Http.Tests/Compono.Http.Tests.csproj
index 022d62ab..5fd8a4c8 100644
--- a/test/Compono.Http.Tests/Compono.Http.Tests.csproj
+++ b/test/Compono.Http.Tests/Compono.Http.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" VersionOverride="2.5.1" />
     <ProjectReference Include="..\..\src\Compono\Compono.csproj" />
     <ProjectReference Include="..\..\src\Compono.Http\Compono.Http.csproj" />
   </ItemGroup>
diff --git a/test/Compono.Logging.Tests/Compono.Logging.Tests.csproj b/test/Compono.Logging.Tests/Compono.Logging.Tests.csproj
index 2b0560cd..01031a44 100644
--- a/test/Compono.Logging.Tests/Compono.Logging.Tests.csproj
+++ b/test/Compono.Logging.Tests/Compono.Logging.Tests.csproj
@@ -40,6 +40,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" VersionOverride="2.5.1" />
     <ProjectReference Include="..\..\src\Compono\Compono.csproj" />
     <ProjectReference Include="..\..\src\Compono.Logging\Compono.Logging.csproj" />
     <!-- Test-only: PLAN-0055 task 13's stage-6 registration-order precedence tests need a second
diff --git a/test/Compono.MSTest.Tests/Compono.MSTest.Tests.csproj b/test/Compono.MSTest.Tests/Compono.MSTest.Tests.csproj
index 1c56ea29..f394af1d 100644
--- a/test/Compono.MSTest.Tests/Compono.MSTest.Tests.csproj
+++ b/test/Compono.MSTest.Tests/Compono.MSTest.Tests.csproj
@@ -27,6 +27,7 @@
          alone - this project actually executes as a real MSTest test run, unlike
          src/Compono.MSTest itself, which only authors against MSTest.TestFramework's
          extensibility surface. -->
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <PackageReference Include="MSTest" />
   </ItemGroup>
 
diff --git a/test/Compono.NSubstitute.Tests/Compono.NSubstitute.Tests.csproj b/test/Compono.NSubstitute.Tests/Compono.NSubstitute.Tests.csproj
index 371c8a1f..c8c1cc5e 100644
--- a/test/Compono.NSubstitute.Tests/Compono.NSubstitute.Tests.csproj
+++ b/test/Compono.NSubstitute.Tests/Compono.NSubstitute.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <ProjectReference Include="..\..\src\Compono.NSubstitute\Compono.NSubstitute.csproj" />
   </ItemGroup>
 
diff --git a/test/Compono.NUnit.Tests/Compono.NUnit.Tests.csproj b/test/Compono.NUnit.Tests/Compono.NUnit.Tests.csproj
index c02dcb93..aca282bf 100644
--- a/test/Compono.NUnit.Tests/Compono.NUnit.Tests.csproj
+++ b/test/Compono.NUnit.Tests/Compono.NUnit.Tests.csproj
@@ -28,6 +28,7 @@
          Microsoft.NET.Test.Sdk for the shared MTP host infrastructure - this project actually
          executes as a real NUnit test run, unlike src/Compono.NUnit itself, which only authors
          against NUnit's own ITestBuilder/IMethodInfo extensibility surface. -->
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <PackageReference Include="NUnit3TestAdapter" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
   </ItemGroup>
diff --git a/test/Compono.Options.Tests/Compono.Options.Tests.csproj b/test/Compono.Options.Tests/Compono.Options.Tests.csproj
index 6da2d626..93599b42 100644
--- a/test/Compono.Options.Tests/Compono.Options.Tests.csproj
+++ b/test/Compono.Options.Tests/Compono.Options.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <ProjectReference Include="..\..\src\Compono\Compono.csproj" />
     <ProjectReference Include="..\..\src\Compono.Options\Compono.Options.csproj" />
   </ItemGroup>
diff --git a/test/Compono.TestDoubles.Tests/Compono.TestDoubles.Tests.csproj b/test/Compono.TestDoubles.Tests/Compono.TestDoubles.Tests.csproj
index e7a37533..5ccc9443 100644
--- a/test/Compono.TestDoubles.Tests/Compono.TestDoubles.Tests.csproj
+++ b/test/Compono.TestDoubles.Tests/Compono.TestDoubles.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <ProjectReference Include="..\..\src\Compono.TestDoubles\Compono.TestDoubles.csproj" />
     <ProjectReference Include="..\..\src\Compono.NSubstitute\Compono.NSubstitute.csproj" />
   </ItemGroup>
diff --git a/test/Compono.Tests/Compono.Tests.csproj b/test/Compono.Tests/Compono.Tests.csproj
index 99dd04cb..ffee4868 100644
--- a/test/Compono.Tests/Compono.Tests.csproj
+++ b/test/Compono.Tests/Compono.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <ProjectReference Include="..\..\src\Compono\Compono.csproj" />
   </ItemGroup>
 
diff --git a/test/Compono.XunitV3.Aot.Tests/Compono.XunitV3.Aot.Tests.csproj b/test/Compono.XunitV3.Aot.Tests/Compono.XunitV3.Aot.Tests.csproj
index 683e674c..f32cd2c8 100644
--- a/test/Compono.XunitV3.Aot.Tests/Compono.XunitV3.Aot.Tests.csproj
+++ b/test/Compono.XunitV3.Aot.Tests/Compono.XunitV3.Aot.Tests.csproj
@@ -24,6 +24,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <PackageReference Include="xunit.v3.aot.mtp-v2" />
   </ItemGroup>
 
diff --git a/test/Compono.XunitV3.Tests/Compono.XunitV3.Tests.csproj b/test/Compono.XunitV3.Tests/Compono.XunitV3.Tests.csproj
index 01a75393..f37d1aa5 100644
--- a/test/Compono.XunitV3.Tests/Compono.XunitV3.Tests.csproj
+++ b/test/Compono.XunitV3.Tests/Compono.XunitV3.Tests.csproj
@@ -17,6 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform.MSBuild" />
     <ProjectReference Include="..\..\src\Compono.XunitV3\Compono.XunitV3.csproj" />
     <!-- A plain ProjectReference to Compono.csproj (transitively, via Compono.XunitV3) does not
          propagate Compono.Generators.dll as an active analyzer - CompositionBuilderShareTests.cs