diff --git a/cc/builder.go b/cc/builder.go
index 8f253ca..1d12b5f 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -252,6 +252,7 @@
 	tidy           bool
 	coverage       bool
 	sAbiDump       bool
+	protoRoot      bool
 
 	systemIncludeFlags string