diff --git a/compiler/cpp/src/generate/t_csharp_generator.cc b/compiler/cpp/src/generate/t_csharp_generator.cc
index 5a910ea..96c0f6e 100644
--- a/compiler/cpp/src/generate/t_csharp_generator.cc
+++ b/compiler/cpp/src/generate/t_csharp_generator.cc
@@ -410,7 +410,7 @@
   indent(out) << "[Serializable]" << endl;
   bool is_final = (tstruct->annotations_.find("final") != tstruct->annotations_.end());
  
-  indent(out) << "public " << (is_final ? "sealed " : "") << "class " << tstruct->get_name() << " : ";
+  indent(out) << "public " << (is_final ? "sealed " : "") << "partial class " << tstruct->get_name() << " : ";
 
   if (is_exception) {
     out << "Exception, ";