diff --git a/build/dependencies.props b/build/dependencies.props
index 0ff09ada17..26152a24c1 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -3,26 +3,26 @@
     <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
   </PropertyGroup>
   <PropertyGroup Label="Package Versions">
-    <InternalAspNetCoreSdkPackageVersion>2.1.0-preview2-15728</InternalAspNetCoreSdkPackageVersion>
-    <MicrosoftAspNetCoreAspNetCoreModulePackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreAspNetCoreModulePackageVersion>
-    <MicrosoftAspNetCoreDiagnosticsPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreDiagnosticsPackageVersion>
-    <MicrosoftAspNetCoreHttpExtensionsPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreHttpExtensionsPackageVersion>
-    <MicrosoftAspNetCoreServerHttpSysPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreServerHttpSysPackageVersion>
-    <MicrosoftAspNetCoreServerIISIntegrationPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreServerIISIntegrationPackageVersion>
-    <MicrosoftAspNetCoreServerIntegrationTestingPackageVersion>0.5.0-preview2-30272</MicrosoftAspNetCoreServerIntegrationTestingPackageVersion>
-    <MicrosoftAspNetCoreServerKestrelHttpsPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreServerKestrelHttpsPackageVersion>
-    <MicrosoftAspNetCoreServerKestrelPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreServerKestrelPackageVersion>
-    <MicrosoftAspNetCoreStaticFilesPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreStaticFilesPackageVersion>
-    <MicrosoftAspNetCoreTestingPackageVersion>2.1.0-preview2-30272</MicrosoftAspNetCoreTestingPackageVersion>
-    <MicrosoftExtensionsConfigurationCommandLinePackageVersion>2.1.0-preview2-30272</MicrosoftExtensionsConfigurationCommandLinePackageVersion>
-    <MicrosoftExtensionsLoggingConsolePackageVersion>2.1.0-preview2-30272</MicrosoftExtensionsLoggingConsolePackageVersion>
-    <MicrosoftExtensionsLoggingPackageVersion>2.1.0-preview2-30272</MicrosoftExtensionsLoggingPackageVersion>
-    <MicrosoftExtensionsLoggingTestingPackageVersion>2.1.0-preview2-30272</MicrosoftExtensionsLoggingTestingPackageVersion>
-    <MicrosoftExtensionsOptionsPackageVersion>2.1.0-preview2-30272</MicrosoftExtensionsOptionsPackageVersion>
+    <InternalAspNetCoreSdkPackageVersion>2.1.0-preview2-15739</InternalAspNetCoreSdkPackageVersion>
+    <MicrosoftAspNetCoreAspNetCoreModulePackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreAspNetCoreModulePackageVersion>
+    <MicrosoftAspNetCoreDiagnosticsPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreDiagnosticsPackageVersion>
+    <MicrosoftAspNetCoreHttpExtensionsPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreHttpExtensionsPackageVersion>
+    <MicrosoftAspNetCoreServerHttpSysPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreServerHttpSysPackageVersion>
+    <MicrosoftAspNetCoreServerIISIntegrationPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreServerIISIntegrationPackageVersion>
+    <MicrosoftAspNetCoreServerIntegrationTestingPackageVersion>0.5.0-preview2-30319</MicrosoftAspNetCoreServerIntegrationTestingPackageVersion>
+    <MicrosoftAspNetCoreServerKestrelHttpsPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreServerKestrelHttpsPackageVersion>
+    <MicrosoftAspNetCoreServerKestrelPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreServerKestrelPackageVersion>
+    <MicrosoftAspNetCoreStaticFilesPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreStaticFilesPackageVersion>
+    <MicrosoftAspNetCoreTestingPackageVersion>2.1.0-preview2-30319</MicrosoftAspNetCoreTestingPackageVersion>
+    <MicrosoftExtensionsConfigurationCommandLinePackageVersion>2.1.0-preview2-30319</MicrosoftExtensionsConfigurationCommandLinePackageVersion>
+    <MicrosoftExtensionsLoggingConsolePackageVersion>2.1.0-preview2-30319</MicrosoftExtensionsLoggingConsolePackageVersion>
+    <MicrosoftExtensionsLoggingPackageVersion>2.1.0-preview2-30319</MicrosoftExtensionsLoggingPackageVersion>
+    <MicrosoftExtensionsLoggingTestingPackageVersion>2.1.0-preview2-30319</MicrosoftExtensionsLoggingTestingPackageVersion>
+    <MicrosoftExtensionsOptionsPackageVersion>2.1.0-preview2-30319</MicrosoftExtensionsOptionsPackageVersion>
     <MicrosoftNETCoreApp20PackageVersion>2.0.0</MicrosoftNETCoreApp20PackageVersion>
-    <MicrosoftNETCoreApp21PackageVersion>2.1.0-preview2-26225-03</MicrosoftNETCoreApp21PackageVersion>
+    <MicrosoftNETCoreApp21PackageVersion>2.1.0-preview2-26308-01</MicrosoftNETCoreApp21PackageVersion>
     <MicrosoftNETTestSdkPackageVersion>15.6.0</MicrosoftNETTestSdkPackageVersion>
-    <SystemNetWebSocketsWebSocketProtocolPackageVersion>4.5.0-preview2-26224-02</SystemNetWebSocketsWebSocketProtocolPackageVersion>
+    <SystemNetWebSocketsWebSocketProtocolPackageVersion>4.5.0-preview2-26308-02</SystemNetWebSocketsWebSocketProtocolPackageVersion>
     <XunitPackageVersion>2.3.1</XunitPackageVersion>
     <XunitRunnerVisualStudioPackageVersion>2.4.0-beta.1.build3945</XunitRunnerVisualStudioPackageVersion>
   </PropertyGroup>
diff --git a/korebuild-lock.txt b/korebuild-lock.txt
index 138d848db1..2c06ab4184 100644
--- a/korebuild-lock.txt
+++ b/korebuild-lock.txt
@@ -1,2 +1,2 @@
-version:2.1.0-preview2-15728
-commithash:393377068ddcf51dfee0536536d455f57a828b06
+version:2.1.0-preview2-15739
+commithash:d8c238a4ac822c643d707d9cf44d2dbc93c59a68
diff --git a/src/Microsoft.AspNetCore.WebSockets/WebSocketMiddleware.cs b/src/Microsoft.AspNetCore.WebSockets/WebSocketMiddleware.cs
index eba9597cd5..a583bccd2b 100644
--- a/src/Microsoft.AspNetCore.WebSockets/WebSocketMiddleware.cs
+++ b/src/Microsoft.AspNetCore.WebSockets/WebSocketMiddleware.cs
@@ -119,7 +119,10 @@ namespace Microsoft.AspNetCore.WebSockets
 
                 Stream opaqueTransport = await _upgradeFeature.UpgradeAsync(); // Sets status code to 101
 
-                return WebSocketProtocol.CreateFromStream(opaqueTransport, isServer: true, subProtocol: subProtocol, keepAliveInterval: keepAliveInterval);
+                // Allocate a buffer for receive (default is 4k)
+                var buffer = new byte[receiveBufferSize];
+
+                return WebSocketProtocol.CreateFromStream(opaqueTransport, isServer: true, subProtocol: subProtocol, keepAliveInterval: keepAliveInterval, buffer: buffer);
             }
         }
     }