diff --git a/Directory.Packages.props b/Directory.Packages.props
index f3ad23c543..f1f5623e44 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -43,7 +43,7 @@
     <PackageVersion Include="Microsoft.TestPlatform.ObjectModel" Version="$(MicrosoftNETTestSdkVersion)" />
     <PackageVersion Include="Microsoft.TestPlatform.TranslationLayer" Version="$(MicrosoftNETTestSdkVersion)" />
     <PackageVersion Include="Microsoft.WindowsAppSDK" Version="1.0.0" />
-    <PackageVersion Include="Polyfill" Version="6.2.3" />
+    <PackageVersion Include="Polyfill" Version="6.9.0" />
     <!-- CVE-2019-0820 -->
     <PackageVersion Include="System.Diagnostics.TextWriterTraceListener" Version="4.3.0" />
     <!-- CVE-2019-0981, CVE-2019-0980, CVE-2019-0657 -->
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/JsonRpc/StreamMessageHandler.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/JsonRpc/StreamMessageHandler.cs
index d056774c55..e092e70a4d 100644
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/JsonRpc/StreamMessageHandler.cs
+++ b/src/Platform/Microsoft.Testing.Platform/ServerMode/JsonRpc/StreamMessageHandler.cs
@@ -3,12 +3,10 @@
 
 using System.Text;
 
-#if !NET8_0_OR_GREATER
-using Microsoft.Testing.Platform.Helpers;
-#endif
-
 #if NETCOREAPP
 using System.Buffers;
+#else
+using Microsoft.Testing.Platform.Helpers;
 #endif
 
 namespace Microsoft.Testing.Platform.ServerMode;
@@ -129,11 +127,7 @@ public async Task WriteRequestAsync(RpcMessage message, CancellationToken cancel
         await _writer.WriteLineAsync("Content-Type: application/testingplatform");
         await _writer.WriteLineAsync();
         await _writer.WriteAsync(messageStr);
-#if NET8_0_OR_GREATER
         await _writer.FlushAsync(cancellationToken);
-#else
-        await _writer.FlushAsync().WithCancellationAsync(cancellationToken);
-#endif
     }
 
     protected virtual void Dispose(bool disposing)