diff --git a/src/main/protobuf/BlogPostMessages.proto b/src/main/protobuf/BlogPostMessages.proto
index bc4069c..a51b4d0 100644
--- a/src/main/protobuf/BlogPostMessages.proto
+++ b/src/main/protobuf/BlogPostMessages.proto
@@ -1,6 +1,8 @@
 /**
  * Copyright (C) 2014-2017 Lightbend Inc. <http://www.lightbend.com>
  */
+syntax = "proto2";
+
 package blog.typed.persistence.scaladsl;
 
 option java_package = "blog.typed.persistence.scaladsl.protobuf";