diff --git a/src/OpenCensus.Exporter.Ocagent/OpenCensus.Exporter.Ocagent.csproj b/src/OpenCensus.Exporter.Ocagent/OpenCensus.Exporter.Ocagent.csproj
index 8215f94..1866b69 100644
--- a/src/OpenCensus.Exporter.Ocagent/OpenCensus.Exporter.Ocagent.csproj
+++ b/src/OpenCensus.Exporter.Ocagent/OpenCensus.Exporter.Ocagent.csproj
@@ -19,7 +19,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\OpenCensus.Abstractions\OpenCensus.Abstractions.csproj" />
-    <PackageReference Include="Google.Protobuf" Version="3.6.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="Grpc.Core" Version="1.16.0" />
     <PackageReference Include="StyleCop.Analyzers" Version="1.1.1-beta.61">
       <PrivateAssets>All</PrivateAssets>