diff --git a/gRPC/csharp/Client/packages.config b/gRPC/csharp/Client/packages.config
index c9e904f..e949570 100644
--- a/gRPC/csharp/Client/packages.config
+++ b/gRPC/csharp/Client/packages.config
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Gnu.Getopt" version="0.9.2" targetFramework="net461" />
-  <package id="Google.Protobuf" version="3.1.0" targetFramework="net461" />
+  <package id="Google.Protobuf" version="3.15.0" targetFramework="net461" />
   <package id="Grpc.Core" version="1.0.0" targetFramework="net461" />
   <package id="Grpc.Tools" version="1.0.0" targetFramework="net461" />
   <package id="Newtonsoft.Json" version="9.0.1" targetFramework="net461" />