diff --git a/lib/letsencrypt-forge.js b/lib/letsencrypt-forge.js
index 2e9c768..122867e 100644
--- a/lib/letsencrypt-forge.js
+++ b/lib/letsencrypt-forge.js
@@ -5,6 +5,7 @@
 'use strict';
 
 var crypto = require("crypto");
+var tls = require("tls");
 var forge = require("node-forge");
 var util = require("./acme-util.js");
 
@@ -359,7 +360,7 @@ module.exports = {
     var privateKey = importPrivateKey(keyPair.privateKey);
     var derCert = bufferToBytes(util.b64dec(cert));
     var realCert = forge.pki.certificateFromAsn1(forge.asn1.fromDer(derCert));
-    return crypto.createCredentials({
+    return tls.createSecureContext({
       key: forge.pki.privateKeyToPem(privateKey),
       cert: forge.pki.certificateToPem(realCert)
     }).context;