diff --git a/cmd/lotus-shed/commp.go b/cmd/lotus-shed/commp.go
index c9808c19a..acc1e73e6 100644
--- a/cmd/lotus-shed/commp.go
+++ b/cmd/lotus-shed/commp.go
@@ -1,7 +1,9 @@
 package main
 
 import (
+	"encoding/hex"
 	"fmt"
+
 	commcid "github.com/filecoin-project/go-fil-commcid"
 	"gopkg.in/urfave/cli.v2"
 )
@@ -10,8 +12,16 @@ var commpToCidCmd = &cli.Command{
 	Name:        "commp-to-cid",
 	Description: "Convert a raw commP to a piece-Cid",
 	Action: func(cctx *cli.Context) error {
-		cp := []byte(cctx.Args().Get(0))
-		fmt.Println(commcid.PieceCommitmentV1ToCID(cp))
+		if !cctx.Args().Present() {
+			return fmt.Errorf("must specify commP to convert")
+		}
+
+		dec, err := hex.DecodeString(cctx.Args().First())
+		if err != nil {
+			return fmt.Errorf("failed to decode input as hex string: %w", err)
+		}
+
+		fmt.Println(commcid.PieceCommitmentV1ToCID(dec))
 		return nil
 	},
 }