diff --git a/IOST.Rpcpb/IOST.Rpcpb.csproj b/IOST.Rpcpb/IOST.Rpcpb.csproj
index 96c56c6..7c3da16 100644
--- a/IOST.Rpcpb/IOST.Rpcpb.csproj
+++ b/IOST.Rpcpb/IOST.Rpcpb.csproj
@@ -7,7 +7,7 @@
 
   <ItemGroup>
     <PackageReference Include="Google.Api.Gax.Grpc" Version="2.9.0" />
-    <PackageReference Include="Google.Protobuf" Version="3.8.0" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="Grpc.Core" Version="1.22.0" />
     <!-- PackageReference Include="Grpc.Tools" Version="1.22.0">
       <PrivateAssets>all</PrivateAssets>