diff --git a/DesignPatternsInCSharp/DesignPatternsInCSharp.csproj b/DesignPatternsInCSharp/DesignPatternsInCSharp.csproj
index 1069082..ccecb4c 100644
--- a/DesignPatternsInCSharp/DesignPatternsInCSharp.csproj
+++ b/DesignPatternsInCSharp/DesignPatternsInCSharp.csproj
@@ -17,7 +17,7 @@
 
   <ItemGroup>
     <PackageReference Include="FluentAssertions" Version="6.6.0" />
-    <PackageReference Include="Google.Protobuf" Version="3.20.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.21.9" />
     <PackageReference Include="Grpc.Net.ClientFactory" Version="2.45.0" />
     <PackageReference Include="Grpc.Tools" Version="2.45.0">
       <PrivateAssets>all</PrivateAssets>