diff --git a/syntax.go b/syntax.go
index 25ffab0..1c38016 100644
--- a/syntax.go
+++ b/syntax.go
@@ -395,8 +395,10 @@ func (s *Syntax) Generate(o GeneratorOptions, w io.Writer) error {
 		hc = headCodeExported
 	}
 
+	fprintln("// head")
 	fprint(hc)
 	fprintln()
+	fprintln("// eo head")
 	fprintln()
 
 	if o.Export {