diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index 227088c7ffd..300c4a85162 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -160,9 +160,9 @@
       <SourceBuild RepoName="source-build-externals" ManagedOnly="true" />
     </Dependency>
     <!-- Intermediate is necessary for source build. -->
-    <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="9.0.0-alpha.1.25266.1">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="9.0.0-alpha.1.25521.3">
       <Uri>https://github.com/dotnet/source-build-reference-packages</Uri>
-      <Sha>2bdf6b694572c45f6249c5406ae2303d678cda3f</Sha>
+      <Sha>a9cadb09ddcc99b1e535efb0648047634f0c4f40</Sha>
       <SourceBuild RepoName="source-build-reference-packages" ManagedOnly="true" />
     </Dependency>
     <!-- Transitive dependency needed for source build. -->
diff --git a/eng/Versions.props b/eng/Versions.props
index c9c2755033e..af4de766d1d 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -26,10 +26,10 @@
     <MicrosoftSymbolUploaderBuildTaskVersion>2.0.0-preview.1.23470.14</MicrosoftSymbolUploaderBuildTaskVersion>
     <MicrosoftSymbolUploaderVersion>2.0.0-preview.1.23470.14</MicrosoftSymbolUploaderVersion>
     <!-- msbuild -->
-    <MicrosoftBuildFrameworkVersion>17.8.29</MicrosoftBuildFrameworkVersion>
-    <MicrosoftBuildTasksCoreVersion>17.8.29</MicrosoftBuildTasksCoreVersion>
-    <MicrosoftBuildUtilitiesCoreVersion>17.8.29</MicrosoftBuildUtilitiesCoreVersion>
-    <MicrosoftBuildVersion>17.8.29</MicrosoftBuildVersion>
+    <MicrosoftBuildFrameworkVersion>17.8.43</MicrosoftBuildFrameworkVersion>
+    <MicrosoftBuildTasksCoreVersion>17.8.43</MicrosoftBuildTasksCoreVersion>
+    <MicrosoftBuildUtilitiesCoreVersion>17.8.43</MicrosoftBuildUtilitiesCoreVersion>
+    <MicrosoftBuildVersion>17.8.43</MicrosoftBuildVersion>
     <!-- netstandard -->
     <NETStandardLibraryVersion>2.0.3</NETStandardLibraryVersion>
     <!-- nuget -->
diff --git a/src/Microsoft.DotNet.SignTool.Tests/FakeSignTool.cs b/src/Microsoft.DotNet.SignTool.Tests/FakeSignTool.cs
index 8bfa4870af6..57a7e6d16e3 100644
--- a/src/Microsoft.DotNet.SignTool.Tests/FakeSignTool.cs
+++ b/src/Microsoft.DotNet.SignTool.Tests/FakeSignTool.cs
@@ -2,9 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
-using System.Diagnostics;
 using System.IO;
-using System.IO.Packaging;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;