diff --git a/cmd/geth/chaincmd.go b/cmd/geth/chaincmd.go
index dcd617a21e..84077cf5a6 100644
--- a/cmd/geth/chaincmd.go
+++ b/cmd/geth/chaincmd.go
@@ -199,6 +199,7 @@ Use "ethereum dump 0" to dump the genesis block.`,
 			utils.RopstenFlag,
 			utils.RinkebyFlag,
 			utils.GoerliFlag,
+			utils.LegacyTestnetFlag,
 			utils.SyncModeFlag,
 		},
 		Category: "BLOCKCHAIN COMMANDS",