add C# test demoing custom error details
diff --git a/src/csharp/generate_proto_csharp.sh b/src/csharp/generate_proto_csharp.sh
index 8caaaab..1a1adbb 100755
--- a/src/csharp/generate_proto_csharp.sh
+++ b/src/csharp/generate_proto_csharp.sh
@@ -37,4 +37,4 @@
# don't match the package names. Setting -I to the correct value src/proto
# breaks the code generation.
$PROTOC --plugin=$PLUGIN --csharp_out=$TESTING_DIR --grpc_out=$TESTING_DIR \
- -I . src/proto/grpc/testing/{control,empty,messages,metrics,payloads,services,stats,test}.proto
+ -I . src/proto/grpc/testing/{control,echo_messages,empty,messages,metrics,payloads,services,stats,test}.proto