diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 3bb65a64ed..ec4dada011 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -162,10 +162,10 @@ var (
 	}
 	NetworkIdFlag = cli.Uint64Flag{
 		Name:  "networkid",
-		Usage: "Network identifier (integer, 1=Frontier, 2=Morden (disused), 3=Ropsten, 4=Rinkeby, 5=Görli)",
+		Usage: "Network identifier (integer, 1=Frontier, 3=Ropsten, 4=Rinkeby, 5=Görli)",
 		Value: eth.DefaultConfig.NetworkId,
 	}
-	LegacyTestnetFlag = cli.BoolFlag{ // Deprecated in favor of --goerli, --rinkeby, or --ropsten
+	LegacyTestnetFlag = cli.BoolFlag{ // TODO(q9f): Remove after Ropsten is discontinued.
 		Name:  "testnet",
 		Usage: "Pre-configured test network (Deprecated: Please choose one of --goerli, --rinkeby, or --ropsten.)",
 	}
@@ -763,7 +763,6 @@ var (
 		Usage: "Comma-separated InfluxDB tags (key/values) attached to all measurements",
 		Value: "host=localhost",
 	}
-
 	EWASMInterpreterFlag = cli.StringFlag{
 		Name:  "vm.ewasm",
 		Usage: "External ewasm configuration (default = built-in interpreter)",
@@ -778,11 +777,18 @@ var (
 
 // MakeDataDir retrieves the currently requested data directory, terminating
 // if none (or the empty string) is specified. If the node is starting a testnet,
-// then a subdirectory of the specified data-dir will be used.
+// then a subdirectory of the specified datadir will be used.
 func MakeDataDir(ctx *cli.Context) string {
 	if path := ctx.GlobalString(DataDirFlag.Name); path != "" {
 		if ctx.GlobalBool(LegacyTestnetFlag.Name) || ctx.GlobalBool(RopstenFlag.Name) {
-			return filepath.Join(path, "testnet")
+			// Maintain compatibility with older Geth configurations storing the
+			// Ropsten database in `testnet` instead of `ropsten`.
+			legacyPath := filepath.Join(path, "testnet")
+			if DatadirExists(legacyPath) {
+				log.Warn("Using the deprecated `testnet` datadir. Future versions will store the Ropsten chain in `ropsten`.")
+				return legacyPath
+			}
+			return filepath.Join(path, "ropsten")
 		}
 		if ctx.GlobalBool(RinkebyFlag.Name) {
 			return filepath.Join(path, "rinkeby")
@@ -1245,7 +1251,14 @@ func setDataDir(ctx *cli.Context, cfg *node.Config) {
 	case ctx.GlobalBool(DeveloperFlag.Name):
 		cfg.DataDir = "" // unless explicitly requested, use memory databases
 	case (ctx.GlobalBool(LegacyTestnetFlag.Name) || ctx.GlobalBool(RopstenFlag.Name)) && cfg.DataDir == node.DefaultDataDir():
-		cfg.DataDir = filepath.Join(node.DefaultDataDir(), "testnet")
+		// Maintain compatibility with older Geth configurations storing the
+		// Ropsten database in `testnet` instead of `ropsten`.
+		legacyPath := filepath.Join(node.DefaultDataDir(), "testnet")
+		if DatadirExists(legacyPath) {
+			cfg.DataDir = legacyPath
+		} else {
+			cfg.DataDir = filepath.Join(node.DefaultDataDir(), "ropsten")
+		}
 	case ctx.GlobalBool(RinkebyFlag.Name) && cfg.DataDir == node.DefaultDataDir():
 		cfg.DataDir = filepath.Join(node.DefaultDataDir(), "rinkeby")
 	case ctx.GlobalBool(GoerliFlag.Name) && cfg.DataDir == node.DefaultDataDir():
@@ -1818,3 +1831,15 @@ func MigrateFlags(action func(ctx *cli.Context) error) func(*cli.Context) error
 		return action(ctx)
 	}
 }
+
+// DatadirExists checks wether the datadir in `path` exists or not.
+//
+// E.g., can be used to determine wether to use the old `testnet` directory for
+// Ropsten or create a new `ropsten` datadir instead.
+func DatadirExists(path string) bool {
+	if _, err := os.Stat(path); !os.IsNotExist(err) {
+		return true
+	} else {
+		return false
+	}
+}