diff --git a/api/api_full.go b/api/api_full.go
index 4a31fe537..2ce7edb9b 100644
--- a/api/api_full.go
+++ b/api/api_full.go
@@ -70,7 +70,8 @@ type FullNode interface {
 	ChainGetBlockMessages(ctx context.Context, blockCid cid.Cid) (*BlockMessages, error)
 
 	// ChainGetParentReceipts returns receipts for messages in parent tipset of
-	// the specified block.
+	// the specified block. The receipts in the list returned is one-to-one with the
+	// messages returned by a call to ChainGetParentMessages with the same blockCid.
 	ChainGetParentReceipts(ctx context.Context, blockCid cid.Cid) ([]*types.MessageReceipt, error)
 
 	// ChainGetParentMessages returns messages stored in parent tipset of the
diff --git a/documentation/en/api-methods.md b/documentation/en/api-methods.md
index 84ac018a8..79aec713d 100644
--- a/documentation/en/api-methods.md
+++ b/documentation/en/api-methods.md
@@ -540,7 +540,8 @@ Response: `null`
 
 ### ChainGetParentReceipts
 ChainGetParentReceipts returns receipts for messages in parent tipset of
-the specified block.
+the specified block. The receipts in the list returned is one-to-one with the
+messages returned by a call to ChainGetParentMessages with the same blockCid.
 
 
 Perms: read