diff --git a/core/Core.csproj b/core/Core.csproj
index d68aae5..d19ccf9 100644
--- a/core/Core.csproj
+++ b/core/Core.csproj
@@ -14,7 +14,7 @@
     <RepositoryUrl>https://github.com/tokenio/sdk-csharp</RepositoryUrl>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.12.3" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="Grpc" Version="2.27.0" />
     <PackageReference Include="Grpc.Core" Version="2.27.0" />
     <PackageReference Include="log4net" Version="2.0.8" />