diff --git a/core/types/receipt.go b/core/types/receipt.go
index 124b5d1515..3aabab516c 100644
--- a/core/types/receipt.go
+++ b/core/types/receipt.go
@@ -378,6 +378,7 @@ func (rs Receipts) DeriveFields(config *params.ChainConfig, hash common.Hash, nu
 	return nil
 }
 
+// ReceiptsToRLP encodes a slice of receipts into RLP.
 func ReceiptsToRLP(receipts []Receipts) []rlp.RawValue {
 	result := make([]rlp.RawValue, 0)
 	for _, receipt := range receipts {