diff --git a/server.go b/server.go
index 992d8aa..896acdf 100644
--- a/server.go
+++ b/server.go
@@ -3,6 +3,8 @@ package dynamiclistener
 import (
 	"bytes"
 	"context"
+	"crypto"
+	"crypto/ecdsa"
 	"crypto/md5"
 	"crypto/rsa"
 	"crypto/tls"
@@ -46,7 +48,7 @@ type server struct {
 	// dynamic config change on refresh
 	activeCert        *tls.Certificate
 	activeCA          *x509.Certificate
-	activeCAKey       *rsa.PrivateKey
+	activeCAKey       crypto.Signer
 	activeCAKeyString string
 	domains           map[string]bool
 }
@@ -91,6 +93,40 @@ func (s *server) CACert() (string, error) {
 	return status.CACert, nil
 }
 
+func marshalPrivateKey(privateKey crypto.Signer) (string, []byte, error) {
+	var (
+		keyType string
+		bytes   []byte
+		err     error
+	)
+	if key, ok := privateKey.(*ecdsa.PrivateKey); ok {
+		keyType = cert.ECPrivateKeyBlockType
+		bytes, err = x509.MarshalECPrivateKey(key)
+	} else if key, ok := privateKey.(*rsa.PrivateKey); ok {
+		keyType = cert.RSAPrivateKeyBlockType
+		bytes = x509.MarshalPKCS1PrivateKey(key)
+	} else {
+		keyType = cert.PrivateKeyBlockType
+		bytes, err = x509.MarshalPKCS8PrivateKey(privateKey)
+	}
+	if err != nil {
+		logrus.Errorf("Unable to marshal private key: %v", err)
+	}
+	return keyType, bytes, err
+}
+
+func newPrivateKey() (crypto.Signer, error) {
+	caKeyBytes, err := cert.MakeEllipticPrivateKeyPEM()
+	if err != nil {
+		return nil, err
+	}
+	caKeyIFace, err := cert.ParsePrivateKeyPEM(caKeyBytes)
+	if err != nil {
+		return nil, err
+	}
+	return caKeyIFace.(crypto.Signer), nil
+}
+
 func (s *server) save() {
 	if s.activeCert != nil {
 		return
@@ -114,7 +150,10 @@ func (s *server) save() {
 	}
 
 	for key, cert := range s.certs {
-		certStr := certToString(cert)
+		certStr, err := certToString(cert)
+		if err != nil {
+			continue
+		}
 		if cfg.GeneratedCerts[key] != certStr {
 			cfg.GeneratedCerts[key] = certStr
 			changed = true
@@ -139,9 +178,14 @@ func (s *server) save() {
 		}
 
 		caKeyBuffer := bytes.Buffer{}
+		keyType, keyBytes, err := marshalPrivateKey(s.activeCAKey)
+		if err != nil {
+			return
+		}
+
 		if err := pem.Encode(&caKeyBuffer, &pem.Block{
-			Type:  cert.RSAPrivateKeyBlockType,
-			Bytes: x509.MarshalPKCS1PrivateKey(s.activeCAKey),
+			Type:  keyType,
+			Bytes: keyBytes,
 		}); err != nil {
 			return
 		}
@@ -198,8 +242,8 @@ func (s *server) userConfigure() error {
 	return nil
 }
 
-func genCA() (*x509.Certificate, *rsa.PrivateKey, error) {
-	caKey, err := cert.NewPrivateKey()
+func genCA() (*x509.Certificate, crypto.Signer, error) {
+	caKey, err := newPrivateKey()
 	if err != nil {
 		return nil, nil, err
 	}
@@ -225,7 +269,7 @@ func (s *server) Update(status *ListenerStatus) error {
 			s.Unlock()
 			return err
 		}
-		s.activeCAKey = cert.PrivateKey.(*rsa.PrivateKey)
+		s.activeCAKey = cert.PrivateKey.(crypto.Signer)
 		s.activeCAKeyString = status.CAKey
 
 		x509Cert, err := x509.ParseCertificate(cert.Certificate[0])
@@ -398,7 +442,7 @@ func (s *server) getCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate, e
 		},
 	}
 
-	key, err := cert.NewPrivateKey()
+	key, err := newPrivateKey()
 	if err != nil {
 		return nil, err
 	}
@@ -603,32 +647,36 @@ func stringToCert(certString string) *tls.Certificate {
 		return nil
 	}
 
-	cert, key := parts[0], parts[1]
-	keyBytes, err := base64.StdEncoding.DecodeString(key)
+	certPart, keyPart := parts[0], parts[1]
+	keyBytes, err := base64.StdEncoding.DecodeString(keyPart)
 	if err != nil {
 		return nil
 	}
 
-	rsaKey, err := x509.ParsePKCS1PrivateKey(keyBytes)
+	key, err := cert.ParsePrivateKeyPEM(keyBytes)
 	if err != nil {
 		return nil
 	}
 
-	certBytes, err := base64.StdEncoding.DecodeString(cert)
+	certBytes, err := base64.StdEncoding.DecodeString(certPart)
 	if err != nil {
 		return nil
 	}
 
 	return &tls.Certificate{
 		Certificate: [][]byte{certBytes},
-		PrivateKey:  rsaKey,
+		PrivateKey:  key,
 	}
 }
 
-func certToString(cert *tls.Certificate) string {
+func certToString(cert *tls.Certificate) (string, error) {
+	_, keyBytes, err := marshalPrivateKey(cert.PrivateKey.(crypto.Signer))
+	if err != nil {
+		return "", err
+	}
 	certString := base64.StdEncoding.EncodeToString(cert.Certificate[0])
-	keyString := base64.StdEncoding.EncodeToString(x509.MarshalPKCS1PrivateKey(cert.PrivateKey.(*rsa.PrivateKey)))
-	return certString + "#" + keyString
+	keyString := base64.StdEncoding.EncodeToString(keyBytes)
+	return certString + "#" + keyString, nil
 }
 
 type tcpKeepAliveListener struct {