diff --git a/pkg/parser/types/immutable_field_types_test.go b/pkg/parser/types/immutable_field_types_test.go
index 663079782b60f..3fd673d8e8062 100644
--- a/pkg/parser/types/immutable_field_types_test.go
+++ b/pkg/parser/types/immutable_field_types_test.go
@@ -32,6 +32,7 @@ type immutable interface {
 	makeMutable() mutable
 }
 
+// ONE is a test structure for interface embedding test.
 type ONE struct {
 }