diff --git a/main.go b/main.go
index 3256b93..00c1276 100644
--- a/main.go
+++ b/main.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"sort"
 	"strings"
 	"text/template"
 	"time"
@@ -15,6 +16,7 @@ import (
 	"github.com/Luzifer/rconfig"
 	log "github.com/Sirupsen/logrus"
 	"github.com/hashicorp/vault/api"
+	"github.com/hashicorp/vault/helper/certutil"
 	homedir "github.com/mitchellh/go-homedir"
 	"github.com/olekukonko/tablewriter"
 )
@@ -24,8 +26,9 @@ const (
 	actionMakeClientConfig = "client"
 	actionMakeServerConfig = "server"
 	actionRevoke           = "revoke"
+	actionRevokeSerial     = "revoke-serial"
 
-	dateFormat = "2006-01-02 15:04:05 -0700"
+	dateFormat = "2006-01-02 15:04:05"
 )
 
 var (
@@ -36,7 +39,7 @@ var (
 		PKIMountPoint string `flag:"pki-mountpoint" default:"/pki" description:"Path the PKI provider is mounted to"`
 		PKIRole       string `flag:"pki-role" default:"openvpn" description:"Role defined in the PKI usable by the token and able to write the specified FQDN"`
 
-		AutoRevoke bool          `flag:"auto-revoke" default:"false" description:"Automatically revoke older certificates for this FQDN"`
+		AutoRevoke bool          `flag:"auto-revoke" default:"true" description:"Automatically revoke older certificates for this FQDN"`
 		CertTTL    time.Duration `flag:"ttl" default:"8760h" description:"Set the TTL for this certificate"`
 
 		LogLevel       string `flag:"log-level" default:"info" description:"Log level to use (debug, info, warning, error)"`
@@ -54,6 +57,22 @@ type templateVars struct {
 	PrivateKey    string
 }
 
+type listCertificatesTableRow struct {
+	FQDN      string
+	NotBefore time.Time
+	NotAfter  time.Time
+	Serial    string
+}
+
+func (l listCertificatesTableRow) ToLine() []string {
+	return []string{
+		l.FQDN,
+		l.NotBefore.Format(dateFormat),
+		l.NotAfter.Format(dateFormat),
+		l.Serial,
+	}
+}
+
 func vaultTokenFromDisk() string {
 	vf, err := homedir.Expand("~/.vault-token")
 	if err != nil {
@@ -96,7 +115,7 @@ func init() {
 func main() {
 	if len(rconfig.Args()) < 2 {
 		fmt.Println("Usage: vault-openvpn [options] <action> <FQDN>")
-		fmt.Println("         actions: client / server / list / revoke")
+		fmt.Println("         actions: client / server / list / revoke / revoke-serial")
 		os.Exit(1)
 	}
 
@@ -121,7 +140,11 @@ func main() {
 
 	switch action {
 	case actionRevoke:
-		if err := revokeOlderCertificate(fqdn); err != nil {
+		if err := revokeCertificateByFQDN(fqdn); err != nil {
+			log.Fatalf("Could not revoke certificate: %s", err)
+		}
+	case actionRevokeSerial:
+		if err := revokeCertificateBySerial(fqdn); err != nil {
 			log.Fatalf("Could not revoke certificate: %s", err)
 		}
 	case actionMakeClientConfig:
@@ -147,42 +170,31 @@ func listCertificates() error {
 	table.SetHeader([]string{"FQDN", "Not Before", "Not After", "Serial"})
 	table.SetBorder(false)
 
-	path := strings.Join([]string{strings.Trim(cfg.PKIMountPoint, "/"), "certs"}, "/")
-	secret, err := client.Logical().List(path)
+	lines := []listCertificatesTableRow{}
+
+	certs, err := fetchValidCertificatesFromVault()
 	if err != nil {
 		return err
 	}
 
-	if secret.Data == nil {
-		return errors.New("Got no data from backend")
+	for _, cert := range certs {
+		lines = append(lines, listCertificatesTableRow{
+			FQDN:      cert.Subject.CommonName,
+			NotBefore: cert.NotBefore,
+			NotAfter:  cert.NotAfter,
+			Serial:    certutil.GetHexFormatted(cert.SerialNumber.Bytes(), ":"),
+		})
 	}
 
-	for _, serial := range secret.Data["keys"].([]interface{}) {
-		path := strings.Join([]string{strings.Trim(cfg.PKIMountPoint, "/"), "cert", serial.(string)}, "/")
-		cs, err := client.Logical().Read(path)
-		if err != nil {
-			return errors.New("Unable to read certificate: " + err.Error())
+	sort.Slice(lines, func(i, j int) bool {
+		if lines[i].FQDN == lines[j].FQDN {
+			return lines[i].NotBefore.Before(lines[j].NotBefore)
 		}
+		return lines[i].FQDN < lines[j].FQDN
+	})
 
-		cert, err := parseCertificate(cs.Data["certificate"].(string))
-		if err != nil {
-			return err
-		}
-
-		if revokationTime, ok := cs.Data["revocation_time"]; ok {
-			rt, err := revokationTime.(json.Number).Int64()
-			if err == nil && rt < time.Now().Unix() && rt > 0 {
-				// Don't display revoked certs
-				continue
-			}
-		}
-
-		table.Append([]string{
-			cert.Subject.CommonName,
-			cert.NotBefore.Format(dateFormat),
-			cert.NotAfter.Format(dateFormat),
-			serial.(string),
-		})
+	for _, line := range lines {
+		table.Append(line.ToLine())
 	}
 
 	table.Render()
@@ -191,7 +203,7 @@ func listCertificates() error {
 
 func generateCertificateConfig(tplName, fqdn string) error {
 	if cfg.AutoRevoke {
-		if err := revokeOlderCertificate(fqdn); err != nil {
+		if err := revokeCertificateByFQDN(fqdn); err != nil {
 			return fmt.Errorf("Could not revoke certificate: %s", err)
 		}
 	}
@@ -229,73 +241,92 @@ func renderTemplate(tplName string, tplv *templateVars) error {
 	return tpl.Execute(os.Stdout, tplv)
 }
 
-func revokeOlderCertificate(fqdn string) error {
+func fetchCertificateBySerial(serial string) (*x509.Certificate, bool, error) {
+	path := strings.Join([]string{strings.Trim(cfg.PKIMountPoint, "/"), "cert", serial}, "/")
+	cs, err := client.Logical().Read(path)
+	if err != nil {
+		return nil, false, fmt.Errorf("Unable to read certificate: %s", err.Error())
+	}
+
+	revoked := false
+	if revokationTime, ok := cs.Data["revocation_time"]; ok {
+		rt, err := revokationTime.(json.Number).Int64()
+		if err == nil && rt < time.Now().Unix() && rt > 0 {
+			// Don't display revoked certs
+			revoked = true
+		}
+	}
+
+	data, _ := pem.Decode([]byte(cs.Data["certificate"].(string)))
+	cert, err := x509.ParseCertificate(data.Bytes)
+	return cert, revoked, err
+}
+
+func fetchValidCertificatesFromVault() ([]*x509.Certificate, error) {
+	res := []*x509.Certificate{}
+
 	path := strings.Join([]string{strings.Trim(cfg.PKIMountPoint, "/"), "certs"}, "/")
 	secret, err := client.Logical().List(path)
+	if err != nil {
+		return res, err
+	}
+
+	if secret.Data == nil {
+		return res, errors.New("Got no data from backend")
+	}
+
+	for _, serial := range secret.Data["keys"].([]interface{}) {
+		cert, revoked, err := fetchCertificateBySerial(serial.(string))
+		if err != nil {
+			return res, err
+		}
+
+		if revoked {
+			continue
+		}
+
+		res = append(res, cert)
+	}
+
+	return res, nil
+}
+
+func revokeCertificateByFQDN(fqdn string) error {
+	certs, err := fetchValidCertificatesFromVault()
 	if err != nil {
 		return err
 	}
 
-	if secret.Data == nil {
-		return errors.New("Got no data from backend")
-	}
-
-	for _, serial := range secret.Data["keys"].([]interface{}) {
-		path := strings.Join([]string{strings.Trim(cfg.PKIMountPoint, "/"), "cert", serial.(string)}, "/")
-		cs, err := client.Logical().Read(path)
-		if err != nil {
-			return errors.New("Unable to read certificate: " + err.Error())
-		}
-
-		cn, err := commonNameFromCertificate(cs.Data["certificate"].(string))
-		if err != nil {
-			return err
-		}
-
-		if revokationTime, ok := cs.Data["revocation_time"]; ok {
-			rt, err := revokationTime.(json.Number).Int64()
-			if err == nil && rt < time.Now().Unix() && rt > 0 {
-				log.WithFields(log.Fields{
-					"cn": cn,
-				}).Debug("Found revoked certificate")
-				continue
-			}
-		}
-
-		log.WithFields(log.Fields{
-			"cn":     cn,
-			"serial": serial,
-		}).Info("Found valid certificate")
-
-		if cn == fqdn {
-			path := strings.Join([]string{strings.Trim(cfg.PKIMountPoint, "/"), "revoke"}, "/")
-			if _, err := client.Logical().Write(path, map[string]interface{}{
-				"serial_number": serial.(string),
-			}); err != nil {
-				return errors.New("Revoke of serial " + serial.(string) + " failed: " + err.Error())
-			}
-			log.WithFields(log.Fields{
-				"cn":     cn,
-				"serial": serial,
-			}).Info("Revoked certificate")
+	for _, cert := range certs {
+		if cert.Subject.CommonName == fqdn {
+			return revokeCertificateBySerial(certutil.GetHexFormatted(cert.SerialNumber.Bytes(), ":"))
 		}
 	}
 
 	return nil
 }
 
-func parseCertificate(pemString string) (*x509.Certificate, error) {
-	data, _ := pem.Decode([]byte(pemString))
-	return x509.ParseCertificate(data.Bytes)
-}
-
-func commonNameFromCertificate(pemString string) (string, error) {
-	cert, err := parseCertificate(pemString)
+func revokeCertificateBySerial(serial string) error {
+	cert, revoked, err := fetchCertificateBySerial(serial)
 	if err != nil {
-		return "", err
+		return err
+	}
+	if revoked {
+		return nil
 	}
 
-	return cert.Subject.CommonName, nil
+	path := strings.Join([]string{strings.Trim(cfg.PKIMountPoint, "/"), "revoke"}, "/")
+	if _, err := client.Logical().Write(path, map[string]interface{}{
+		"serial_number": serial,
+	}); err != nil {
+		return fmt.Errorf("Revoke of serial %q failed: %s", serial, err.Error())
+	}
+	log.WithFields(log.Fields{
+		"cn":     cert.Subject.CommonName,
+		"serial": serial,
+	}).Info("Revoked certificate")
+
+	return nil
 }
 
 func getCACert() (string, error) {