diff --git a/samples/GRPCClient/GRPCClient.csproj b/samples/GRPCClient/GRPCClient.csproj
index 44cc631..a78b793 100644
--- a/samples/GRPCClient/GRPCClient.csproj
+++ b/samples/GRPCClient/GRPCClient.csproj
@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.11.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="Grpc.Net.Client" Version="2.25.0" />
     <PackageReference Include="Grpc.Tools" Version="2.25.0">
       <PrivateAssets>all</PrivateAssets>