diff --git a/src/google/protobuf/unittest.proto b/src/google/protobuf/unittest.proto
index 58f449cf8a..fa95bbdf63 100644
--- a/src/google/protobuf/unittest.proto
+++ b/src/google/protobuf/unittest.proto
@@ -888,6 +888,7 @@ message TestRequiredOneof {
     int32 foo_int = 1;
     string foo_string = 2;
     NestedMessage foo_message = 3;
+    NestedMessage foo_lazy_message = 4 [lazy = true];
   }
   message NestedMessage {
     required double required_double = 1;