diff --git a/build/dependencies.props b/build/dependencies.props
index 2d9e79f9d5..b205cdc605 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -138,7 +138,7 @@
     <IdentityServer4PackageVersion>2.3.0</IdentityServer4PackageVersion>
     <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>
     <MicrosoftAspNetCoreAspNetCoreModuleStablePackageVersion>2.2.0</MicrosoftAspNetCoreAspNetCoreModuleStablePackageVersion>
     <MicrosoftAspNetCoreAspNetCoreModuleV2StablePackageVersion>2.2.0</MicrosoftAspNetCoreAspNetCoreModuleV2StablePackageVersion>
diff --git a/build/sources.props b/build/sources.props
index d9a56c4594..8ef74de40a 100644
--- a/build/sources.props
+++ b/build/sources.props
@@ -22,7 +22,7 @@
       https://dotnet.myget.org/F/roslyn/api/v3/index.json;
       https://dotnet.myget.org/F/roslyn-tools/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>
 
     <PublicCoreFeedPrefix>https://dotnetcli.blob.core.windows.net/dotnet/</PublicCoreFeedPrefix>
diff --git a/eng/Dependencies.props b/eng/Dependencies.props
index 8d72e7e495..826d10ce54 100644
--- a/eng/Dependencies.props
+++ b/eng/Dependencies.props
@@ -107,6 +107,7 @@ and are generated based on the last package release.
     <LatestPackageReference Include="IdentityServer4.AspNetIdentity" Version="$(IdentityServer4AspNetIdentityPackageVersion)" />
     <LatestPackageReference Include="IdentityServer4.EntityFramework" Version="$(IdentityServer4EntityFrameworkPackageVersion)" />
     <LatestPackageReference Include="IdentityServer4" Version="$(IdentityServer4PackageVersion)" />
+    <LatestPackageReference Include="MessagePack" Version="$(MessagePackPackageVersion)" />
     <LatestPackageReference Include="Microsoft.NET.Test.Sdk" Version="$(MicrosoftNETTestSdkPackageVersion)" />
     <LatestPackageReference Include="Moq" Version="$(MoqPackageVersion)" />
     <!-- This version is required by MSBuild tasks or Visual Studio extensions. -->
diff --git a/eng/PatchConfig.props b/eng/PatchConfig.props
index 250b506c12..cca6cdea56 100644
--- a/eng/PatchConfig.props
+++ b/eng/PatchConfig.props
@@ -54,6 +54,9 @@ Later on, this will be checked using this condition:
       Microsoft.AspNetCore.AspNetCoreModule;
       Microsoft.AspNetCore.AspNetCoreModuleV2;
       java:signalr;
+      Microsoft.AspNetCore.SignalR.Protocols.MessagePack;
+      Microsoft.AspNetCore.SignalR.Redis;
+      Microsoft.AspNetCore.SignalR.StackExchangeRedis;
     </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 d4e29baf92..daeeee5132 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;
             }