diff --git a/DuplexCalculator/CalculatorCore/src/CalculatorCore.Client/CalculatorCore.Client.csproj b/DuplexCalculator/CalculatorCore/src/CalculatorCore.Client/CalculatorCore.Client.csproj
index fc1ace5..609dc46 100644
--- a/DuplexCalculator/CalculatorCore/src/CalculatorCore.Client/CalculatorCore.Client.csproj
+++ b/DuplexCalculator/CalculatorCore/src/CalculatorCore.Client/CalculatorCore.Client.csproj
@@ -3,7 +3,7 @@
     <TargetFrameworks>netstandard2.1;net45</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.11.2" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="Grpc.Tools" Version="2.26.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>