diff --git a/cmd/app/serve.go b/cmd/app/serve.go
index 881ef68ee..516ce4e02 100644
--- a/cmd/app/serve.go
+++ b/cmd/app/serve.go
@@ -109,7 +109,7 @@ func newServeCmd() *cobra.Command {
 	cmd.Flags().String("grpc-tls-certificate", "", "the certificate file to use for secure connections - only applies to grpc-port")
 	cmd.Flags().String("grpc-tls-key", "", "the private key file to use for secure connections (without passphrase) - only applies to grpc-port")
 	cmd.Flags().Duration("idle-connection-timeout", 30*time.Second, "The time allowed for connections (HTTP or gRPC) to go idle before being closed by the server")
-	cmd.Flags().String("tls-ca-cert", "", "Path to TLS CA certificate")
+	cmd.Flags().String("ct-log.tls-ca-cert", "", "Path to TLS CA certificate used to connect to ct-log")
 
 	// convert "http-host" flag to "host" and "http-port" flag to be "port"
 	cmd.Flags().SetNormalizeFunc(func(_ *pflag.FlagSet, name string) pflag.NormalizedName {