diff --git a/demos/net5/GrpcDemo/GrpcClient/GrpcClient.csproj b/demos/net5/GrpcDemo/GrpcClient/GrpcClient.csproj
index 2d2cf30..c0b7d5f 100644
--- a/demos/net5/GrpcDemo/GrpcClient/GrpcClient.csproj
+++ b/demos/net5/GrpcDemo/GrpcClient/GrpcClient.csproj
@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.15.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.6" />
     <PackageReference Include="Grpc.Net.ClientFactory" Version="2.35.0" />
     <PackageReference Include="Grpc.Tools" Version="2.36.1">
       <PrivateAssets>all</PrivateAssets>
diff --git a/demos/net5/GrpcDemo/GrpcClientHosted/GrpcClientHosted.csproj b/demos/net5/GrpcDemo/GrpcClientHosted/GrpcClientHosted.csproj
index 11f283a..3920898 100644
--- a/demos/net5/GrpcDemo/GrpcClientHosted/GrpcClientHosted.csproj
+++ b/demos/net5/GrpcDemo/GrpcClientHosted/GrpcClientHosted.csproj
@@ -16,7 +16,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.15.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.6" />
     <PackageReference Include="Grpc.Net.ClientFactory" Version="2.35.0" />
     <PackageReference Include="Grpc.Tools" Version="2.36.1">
       <PrivateAssets>all</PrivateAssets>