diff --git a/indexer/ipld/shared.go b/indexer/ipld/shared.go
index 6e5920e..9d82e12 100644
--- a/indexer/ipld/shared.go
+++ b/indexer/ipld/shared.go
@@ -37,7 +37,7 @@ const (
 	MEthStorageTrie     = 0x98
 	MEthLogTrie         = 0x99
 	MEthLog             = 0x9a
-	MEthWithdrawal      = 0x9b // TODO
+	MEthWithdrawal      = 0x9b // TODO add to multicodec registry
 )
 
 // RawdataToCid takes the desired codec and a slice of bytes