diff --git a/types/validator_set.go b/types/validator_set.go
index 7d019e02e..214e073d0 100644
--- a/types/validator_set.go
+++ b/types/validator_set.go
@@ -23,6 +23,7 @@ import (
 // TODO: consider validator Accum overflow
 // TODO: move valset into an iavl tree where key is 'blockbonded|pubkey'
 type ValidatorSet struct {
+	// NOTE: persisted via reflect, must be exported.
 	Validators []*Validator `json:"validators"`
 	Proposer   *Validator   `json:"proposer"`