diff --git a/build/dependencies.props b/build/dependencies.props
index 8691d498a5..36524c989a 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -17,7 +17,7 @@
     <MicrosoftAspNetCoreTestHostPackageVersion>2.1.0-preview2-30220</MicrosoftAspNetCoreTestHostPackageVersion>
     <MicrosoftAspNetCoreTestingPackageVersion>2.1.0-preview2-30220</MicrosoftAspNetCoreTestingPackageVersion>
     <MicrosoftAspNetCoreWebUtilitiesPackageVersion>2.1.0-preview2-30220</MicrosoftAspNetCoreWebUtilitiesPackageVersion>
-    <MicrosoftExtensionsBuffersSourcesPackageVersion>2.1.0-preview2-30220</MicrosoftExtensionsBuffersSourcesPackageVersion>
+    <MicrosoftExtensionsBuffersSourcesPackageVersion>2.1.0-preview2-pk-corefx0-16426</MicrosoftExtensionsBuffersSourcesPackageVersion>
     <MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion>2.1.0-preview2-30220</MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion>
     <MicrosoftExtensionsConfigurationJsonPackageVersion>2.1.0-preview2-30220</MicrosoftExtensionsConfigurationJsonPackageVersion>
     <MicrosoftExtensionsLoggingAbstractionsPackageVersion>2.1.0-preview2-30220</MicrosoftExtensionsLoggingAbstractionsPackageVersion>
@@ -29,17 +29,17 @@
     <MicrosoftExtensionsPlatformAbstractionsPackageVersion>1.1.0</MicrosoftExtensionsPlatformAbstractionsPackageVersion>
     <MicrosoftExtensionsSecurityHelperSourcesPackageVersion>2.1.0-preview2-30220</MicrosoftExtensionsSecurityHelperSourcesPackageVersion>
     <MicrosoftNETCoreApp20PackageVersion>2.0.0</MicrosoftNETCoreApp20PackageVersion>
-    <MicrosoftNETCoreApp21PackageVersion>2.1.0-preview2-26225-03</MicrosoftNETCoreApp21PackageVersion>
+    <MicrosoftNETCoreApp21PackageVersion>2.1.0-preview2-26308-01</MicrosoftNETCoreApp21PackageVersion>
     <MicrosoftNetHttpHeadersPackageVersion>2.1.0-preview2-30220</MicrosoftNetHttpHeadersPackageVersion>
     <MicrosoftNETTestSdkPackageVersion>15.6.0</MicrosoftNETTestSdkPackageVersion>
     <MicrosoftWebAdministrationPackageVersion>7.0.0</MicrosoftWebAdministrationPackageVersion>
-    <SystemBuffersPackageVersion>4.5.0-preview2-26224-02</SystemBuffersPackageVersion>
-    <SystemIOPipelinesPackageVersion>4.5.0-preview2-26224-02</SystemIOPipelinesPackageVersion>
+    <SystemBuffersPackageVersion>4.5.0-preview2-26308-02</SystemBuffersPackageVersion>
+    <SystemIOPipelinesPackageVersion>4.5.0-preview2-26308-02</SystemIOPipelinesPackageVersion>
     <SystemManagementAutomationPackageVersion>6.1.7601.17515</SystemManagementAutomationPackageVersion>
-    <SystemMemoryPackageVersion>4.5.0-preview2-26224-02</SystemMemoryPackageVersion>
-    <SystemNumericsVectorsPackageVersion>4.5.0-preview2-26224-02</SystemNumericsVectorsPackageVersion>
-    <SystemRuntimeCompilerServicesUnsafePackageVersion>4.5.0-preview2-26224-02</SystemRuntimeCompilerServicesUnsafePackageVersion>
-    <SystemSecurityPrincipalWindowsPackageVersion>4.5.0-preview2-26224-02</SystemSecurityPrincipalWindowsPackageVersion>
+    <SystemMemoryPackageVersion>4.5.0-preview2-26308-02</SystemMemoryPackageVersion>
+    <SystemNumericsVectorsPackageVersion>4.5.0-preview2-26308-02</SystemNumericsVectorsPackageVersion>
+    <SystemRuntimeCompilerServicesUnsafePackageVersion>4.5.0-preview2-26308-02</SystemRuntimeCompilerServicesUnsafePackageVersion>
+    <SystemSecurityPrincipalWindowsPackageVersion>4.5.0-preview2-26308-02</SystemSecurityPrincipalWindowsPackageVersion>
     <XunitPackageVersion>2.3.1</XunitPackageVersion>
     <XunitRunnerVisualStudioPackageVersion>2.4.0-beta.1.build3945</XunitRunnerVisualStudioPackageVersion>
   </PropertyGroup>
diff --git a/src/Microsoft.AspNetCore.Server.IISIntegration/Server/OutputProducer.cs b/src/Microsoft.AspNetCore.Server.IISIntegration/Server/OutputProducer.cs
index b0de146f11..f956d4bfb7 100644
--- a/src/Microsoft.AspNetCore.Server.IISIntegration/Server/OutputProducer.cs
+++ b/src/Microsoft.AspNetCore.Server.IISIntegration/Server/OutputProducer.cs
@@ -16,6 +16,7 @@ namespace Microsoft.AspNetCore.Server.IISIntegration
         // This locks access to to all of the below fields
         private readonly object _contextLock = new object();
 
+        private ValueTask<FlushResult> _flushTask;
         private bool _completed = false;
 
         private readonly Pipe _pipe;
@@ -99,7 +100,7 @@ namespace Microsoft.AspNetCore.Server.IISIntegration
             return FlushAsyncAwaited(awaitable, cancellationToken);
         }
 
-        private async Task FlushAsyncAwaited(PipeAwaiter<FlushResult> awaitable, CancellationToken cancellationToken)
+        private async Task FlushAsyncAwaited(ValueTask<FlushResult> awaitable, CancellationToken cancellationToken)
         {
             // https://github.com/dotnet/corefxlab/issues/1334
             // Since the flush awaitable doesn't currently support multiple awaiters
@@ -107,21 +108,42 @@ namespace Microsoft.AspNetCore.Server.IISIntegration
             // All awaiters get the same task
             lock (_flushLock)
             {
+                _flushTask = awaitable;
                 if (_flushTcs == null || _flushTcs.Task.IsCompleted)
                 {
                     _flushTcs = new TaskCompletionSource<object>();
-                    awaitable.OnCompleted(_flushCompleted);
+
+                    _flushTask.GetAwaiter().OnCompleted(_flushCompleted);
                 }
             }
 
-            await _flushTcs.Task;
-
-            cancellationToken.ThrowIfCancellationRequested();
+            try
+            {
+                await _flushTcs.Task;
+                cancellationToken.ThrowIfCancellationRequested();
+            }
+            catch (OperationCanceledException)
+            {
+                _completed = true;
+                throw;
+            }
         }
 
         private void OnFlushCompleted()
         {
-            _flushTcs.TrySetResult(null);
+            try
+            {
+                _flushTask.GetAwaiter().GetResult();
+                _flushTcs.TrySetResult(null);
+            }
+            catch (Exception exception)
+            {
+                _flushTcs.TrySetResult(exception);
+            }
+            finally
+            {
+                _flushTask = default;
+            }
         }
     }
 }