diff --git a/cmd/geth/chaincmd.go b/cmd/geth/chaincmd.go
index 87863750615ab..a3016c4b091f9 100644
--- a/cmd/geth/chaincmd.go
+++ b/cmd/geth/chaincmd.go
@@ -384,12 +384,12 @@ func parseDumpConfig(ctx *cli.Context, stack *node.Node) (*state.DumpConfig, eth
 				return nil, nil, common.Hash{}, fmt.Errorf("block %x not found", hash)
 			}
 		} else {
-			number, err := strconv.Atoi(arg)
+			number, err := strconv.ParseUint(arg, 10, 64)
 			if err != nil {
 				return nil, nil, common.Hash{}, err
 			}
-			if hash := rawdb.ReadCanonicalHash(db, uint64(number)); hash != (common.Hash{}) {
-				header = rawdb.ReadHeader(db, hash, uint64(number))
+			if hash := rawdb.ReadCanonicalHash(db, number); hash != (common.Hash{}) {
+				header = rawdb.ReadHeader(db, hash, number)
 			} else {
 				return nil, nil, common.Hash{}, fmt.Errorf("header for block %d not found", number)
 			}