diff --git a/build/dependencies.props b/build/dependencies.props
index b5f376321702e3907266e1865da73cef9e33c160..d120513bd468f48d27ffeddc685769d724e87301 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -108,7 +108,7 @@
     <FSharpCorePackageVersion>4.2.1</FSharpCorePackageVersion>
     <GoogleProtobufPackageVersion>3.1.0</GoogleProtobufPackageVersion>
     <LibuvPackageVersion>1.10.0</LibuvPackageVersion>
-    <MessagePackPackageVersion>1.7.3.4</MessagePackPackageVersion>
+    <MessagePackPackageVersion>1.7.3.7</MessagePackPackageVersion>
     <MicrosoftApplicationInsightsAspNetCorePackageVersion>2.1.1</MicrosoftApplicationInsightsAspNetCorePackageVersion>
     <MicrosoftAspNetIdentityEntityFrameworkPackageVersion>2.2.1</MicrosoftAspNetIdentityEntityFrameworkPackageVersion>
     <MicrosoftAspNetWebApiClientPackageVersion>5.2.6</MicrosoftAspNetWebApiClientPackageVersion>
diff --git a/build/sources.props b/build/sources.props
index 5b458ddf090d512a1fda6055379031bc82c49b60..7648381d3be6066c23c65ff6e7fbe197cc93710a 100644
--- a/build/sources.props
+++ b/build/sources.props
@@ -19,7 +19,7 @@
       https://dotnet.myget.org/F/aspnetcore-master/api/v3/index.json;
       https://dotnet.myget.org/F/roslyn/api/v3/index.json;
       https://vside.myget.org/F/vssdk/api/v3/index.json;
-      https://vside.myget.org/F/vsmac/api/v3/index.json
+      https://vside.myget.org/F/vsmac/api/v3/index.json;
     </RestoreSources>
   </PropertyGroup>
 </Project>
diff --git a/eng/Dependencies.props b/eng/Dependencies.props
index e98d42be14d8f1084bb844c4bab250131fdcbae3..2f7b478d680a6f482e84cb0654dd7814563ba17b 100644
--- a/eng/Dependencies.props
+++ b/eng/Dependencies.props
@@ -98,6 +98,7 @@ and are generated based on the last package release.
     <LatestPackageReference Include="AngleSharp" Version="$(AngleSharpPackageVersion)" />
     <LatestPackageReference Include="BenchmarkDotNet" Version="$(BenchmarkDotNetPackageVersion)" />
     <LatestPackageReference Include="FSharp.Core" Version="$(FSharpCorePackageVersion)" />
+    <LatestPackageReference Include="MessagePack" Version="$(MessagePackPackageVersion)" />
     <LatestPackageReference Include="Microsoft.NET.Test.Sdk" Version="$(MicrosoftNETTestSdkPackageVersion)" />
     <LatestPackageReference Include="Moq" Version="$(MoqPackageVersion)" />
     <LatestPackageReference Include="Google.ProtoBuf" Version="$(GoogleProtoBufPackageVersion)" />
diff --git a/eng/PatchConfig.props b/eng/PatchConfig.props
index 29e74d4f858b207d5b449839823caa14c2408603..c25500cb917d5cebeddef67155938be9a29703f8 100644
--- a/eng/PatchConfig.props
+++ b/eng/PatchConfig.props
@@ -28,6 +28,8 @@ Later on, this will be checked using this condition:
   </PropertyGroup>
   <PropertyGroup Condition=" '$(VersionPrefix)' == '2.1.11' ">
     <PackagesInPatch>
+      Microsoft.AspNetCore.SignalR.Protocols.MessagePack;
+      Microsoft.AspNetCore.SignalR.Redis;
     </PackagesInPatch>
   </PropertyGroup>
 
diff --git a/src/SignalR/common/Protocols.MessagePack/src/Protocol/MessagePackHubProtocol.cs b/src/SignalR/common/Protocols.MessagePack/src/Protocol/MessagePackHubProtocol.cs
index 0b693605bf649f6cc2cb46903e2e134e10d32479..36e4886e42b045ebb326248f393d0a878f497126 100644
--- a/src/SignalR/common/Protocols.MessagePack/src/Protocol/MessagePackHubProtocol.cs
+++ b/src/SignalR/common/Protocols.MessagePack/src/Protocol/MessagePackHubProtocol.cs
@@ -245,14 +245,13 @@ namespace Microsoft.AspNetCore.SignalR.Protocol
             var headerCount = ReadMapLength(input, ref offset, "headers");
             if (headerCount > 0)
             {
-                // If headerCount is larger than int.MaxValue, things are going to go horribly wrong anyway :)
-                var headers = new Dictionary<string, string>((int)headerCount, StringComparer.Ordinal);
+                var headers = new Dictionary<string, string>(StringComparer.Ordinal);
 
                 for (var i = 0; i < headerCount; i++)
                 {
                     var key = ReadString(input, ref offset, $"headers[{i}].Key");
                     var value = ReadString(input, ref offset, $"headers[{i}].Value");
-                    headers[key] = value;
+                    headers.Add(key, value);
                 }
                 return headers;
             }