diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 6527d21dcd..8ff3af4bb7 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -1311,6 +1311,9 @@ func setTxPool(ctx *cli.Context, cfg *core.TxPoolConfig) {
 }
 
 func setEthash(ctx *cli.Context, cfg *eth.Config) {
+	if ctx.GlobalIsSet(FakePoWFlag.Name) {
+		cfg.Ethash.PowMode = ethash.ModeFake
+	}
 	if ctx.GlobalIsSet(EthashCacheDirFlag.Name) {
 		cfg.Ethash.CacheDir = ctx.GlobalString(EthashCacheDirFlag.Name)
 	}