diff --git a/lib/client.js b/lib/client.js
index f86bfff..6c99fa5 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -104,6 +104,11 @@ Acme.prototype.post=function(url, body, cb) {
 
 
 function registerNewAccount(state, options, cb) {
+  var state = {};
+
+  if (!options.accountPrivateKeyPem) {
+    return handleErr(new Error("options.accountPrivateKeyPem must be an ascii private key pem"));
+  }
   if (!options.agreeToTerms) {
     cb(new Error("options.agreeToTerms must be function (tosUrl, fn => (err, true))"));
     return;
@@ -117,6 +122,10 @@ function registerNewAccount(state, options, cb) {
     return;
   }
 
+  state.accountKeyPem=options.accountPrivateKeyPem;
+  state.accountKeyPair=cryptoUtil.importPemPrivateKey(state.accountKeyPEM);
+  state.acme=new Acme(state.accountKeyPair);
+
   register();
 
   function register() {
@@ -216,7 +225,11 @@ function getCert(options, cb) {
   if (!options.removeChallenge) {
     return handleErr(new Error("options.removeChallenge must be function(hostname, challengeKey, done) {}"));
   }
+  if (!(options.domains && options.domains.length)) {
+    return handleErr(new Error("options.domains must be an array of domains such as ['example.com', 'www.example.com']"));
+  }
 
+  state.domains = options.domains.slice(0); // copy array
   try {
     state.accountKeyPem=options.accountPrivateKeyPem;
     state.accountKeyPair=cryptoUtil.importPemPrivateKey(state.accountKeyPEM);