diff --git a/Backgammon.AppHost/Backgammon.AppHost.csproj b/Backgammon.AppHost/Backgammon.AppHost.csproj
index 5e55f1d..998189c 100644
--- a/Backgammon.AppHost/Backgammon.AppHost.csproj
+++ b/Backgammon.AppHost/Backgammon.AppHost.csproj
@@ -12,6 +12,7 @@
     <PackageReference Include="Aspire.Hosting.Orleans" Version="13.3.5" />
     <PackageReference Include="Aspire.Hosting.PostgreSQL" Version="13.3.5" />
     <PackageReference Include="Aspire.Hosting.Redis" Version="13.3.5" />
+    <PackageReference Include="MessagePack" Version="2.5.301" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/Backgammon.Server/Backgammon.Server.csproj b/Backgammon.Server/Backgammon.Server.csproj
index fd54154..77211ae 100644
--- a/Backgammon.Server/Backgammon.Server.csproj
+++ b/Backgammon.Server/Backgammon.Server.csproj
@@ -23,6 +23,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="MessagePack" Version="2.5.301" />
     <PackageReference Include="Microsoft.Orleans.Server" Version="9.*" />
     <PackageReference Include="Microsoft.Orleans.Persistence.AdoNet" Version="9.*" />
     <PackageReference Include="Npgsql" Version="10.*" />