diff --git a/Makefile.am b/Makefile.am
index 3c5ce07b07f4..62e8a782dd0d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -107,6 +107,7 @@ csharp_EXTRA_DIST=                                                           \
   csharp/src/Google.Protobuf.Test/FieldCodecTest.cs                          \
   csharp/src/Google.Protobuf.Test/FieldMaskTreeTest.cs                       \
   csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs                    \
+  csharp/src/Google.Protobuf.Test/GeneratedMessageTest.Proto2.cs             \
   csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj                \
   csharp/src/Google.Protobuf.Test/IssuesTest.cs                              \
   csharp/src/Google.Protobuf.Test/JsonFormatterTest.cs                       \