diff --git a/Directory.Packages.props b/Directory.Packages.props
index 64ad5b4..8c503fe 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -35,7 +35,8 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" Version="5.6.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="5.6.0" />
     <!-- Compile-time only: MSBuildLocator resolves the MSBuild assemblies from the installed .NET SDK at run time. -->
-    <PackageVersion Include="Microsoft.Build.Framework" Version="17.11.48" />
+    <PackageVersion Include="Microsoft.Build.Framework" Version="18.9.6" />
+    <PackageVersion Include="Microsoft.NET.StringTools" Version="18.9.6" />
     <!-- Analysis -->
     <PackageVersion Include="StyleCop.Analyzers" Version="1.2.0-beta.556" NoWarn="NU5104" />
     <PackageVersion Include="Roslynator.Analyzers" Version="4.15.0" />
diff --git a/Source/Cli.Specs/Cli.Specs.csproj b/Source/Cli.Specs/Cli.Specs.csproj
index 147ca70..596cfd0 100644
--- a/Source/Cli.Specs/Cli.Specs.csproj
+++ b/Source/Cli.Specs/Cli.Specs.csproj
@@ -15,6 +15,7 @@
     <ItemGroup>
         <!-- MSBuildLocator refuses to run with a copy of this beside the test host; it comes from the SDK. -->
         <PackageReference Include="Microsoft.Build.Framework" ExcludeAssets="runtime" PrivateAssets="all" />
+        <PackageReference Include="Microsoft.NET.StringTools" ExcludeAssets="runtime" PrivateAssets="all" />
         <PackageReference Include="Cratis.Specifications.XUnit" />
         <PackageReference Include="xunit" />
         <PackageReference Include="xunit.runner.visualstudio" />
diff --git a/Source/Cli/Cli.csproj b/Source/Cli/Cli.csproj
index b9f5894..19704da 100644
--- a/Source/Cli/Cli.csproj
+++ b/Source/Cli/Cli.csproj
@@ -56,6 +56,7 @@
         <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" />
         <!-- MSBuild itself must come from the installed SDK that MSBuildLocator registers, never from the output folder. -->
         <PackageReference Include="Microsoft.Build.Framework" ExcludeAssets="runtime" PrivateAssets="all" />
+        <PackageReference Include="Microsoft.NET.StringTools" ExcludeAssets="runtime" PrivateAssets="all" />
         <!--
             The repository default treats Workspaces.Common as an analyzer-only dependency, and PrivateAssets="all"
             keeps Microsoft.CodeAnalysis.Workspaces.dll out of publish output while still copying it on build - so a