diff --git a/lib/acme-util.js b/lib/acme-util.js
index d763698..9c4976f 100644
--- a/lib/acme-util.js
+++ b/lib/acme-util.js
@@ -2,6 +2,7 @@
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
+'use strict';
 
 module.exports = {
 
@@ -29,7 +30,7 @@ module.exports = {
   },
 
   isB64String: function(x) {
-    return (typeof(x) == "string") && !x.match(/[^a-zA-Z0-9_-]/);
+    return ("string" === typeof x) && !x.match(/[^a-zA-Z0-9_-]/);
   },
 
   fieldsPresent: function(fields, object) {
@@ -42,19 +43,19 @@ module.exports = {
   },
 
   validSignature: function(sig) {
-    return ((typeof(sig) == "object") &&
-      ("alg" in sig) && (typeof(sig.alg) == "string") &&
+    return (("object" === typeof sig) &&
+      ("alg" in sig) && ("string" === typeof sig.alg) &&
       ("nonce" in sig) && this.isB64String(sig.nonce) &&
       ("sig" in sig) && this.isB64String(sig.sig) &&
       ("jwk" in sig) && this.validJWK(sig.jwk));
   },
 
   validJWK: function(jwk) {
-    return ((typeof(jwk) == "object") && ("kty" in jwk) && (
-      ((jwk.kty == "RSA")
+    return (("object" === typeof jwk) && ("kty" in jwk) && (
+      ((jwk.kty === "RSA")
         && ("n" in jwk) && this.isB64String(jwk.n)
         && ("e" in jwk) && this.isB64String(jwk.e)) ||
-      ((jwk.kty == "EC")
+      ((jwk.kty === "EC")
         && ("crv" in jwk)
         && ("x" in jwk) && this.isB64String(jwk.x)
         && ("y" in jwk) && this.isB64String(jwk.y))
diff --git a/lib/letsencrypt-forge.js b/lib/letsencrypt-forge.js
index 4db0fee..2e9c768 100644
--- a/lib/letsencrypt-forge.js
+++ b/lib/letsencrypt-forge.js
@@ -9,7 +9,7 @@ var forge = require("node-forge");
 var util = require("./acme-util.js");
 
 var TOKEN_SIZE = 16;
-var NONCE_SIZE = 16;
+//var NONCE_SIZE = 16;
 
 function bytesToBuffer(bytes) {
   return new Buffer(forge.util.bytesToHex(bytes), "hex");
@@ -29,7 +29,7 @@ function base64ToBytes(base64) {
 
 function bnToBase64(bn) {
   var hex = bn.toString(16);
-  if (hex.length % 2 == 1) { hex = "0" + hex; }
+  if (hex.length % 2 === 1) { hex = "0" + hex; }
   return util.b64enc(new Buffer(hex, "hex"));
 }
 
@@ -140,7 +140,7 @@ module.exports = {
 
   thumbprint: function(publicKey) {
     // Only handling RSA keys
-    input = bytesToBuffer('{"e":"'+ publicKey.e + '","kty":"RSA","n":"'+ publicKey.n +'"}');
+    var input = bytesToBuffer('{"e":"'+ publicKey.e + '","kty":"RSA","n":"'+ publicKey.n +'"}');
     return util.b64enc(crypto.createHash('sha256').update(input).digest());
   },
 
@@ -170,10 +170,12 @@ module.exports = {
       protected: protected64,
       payload: payload64,
       signature: util.b64enc(bytesToBuffer(sig)),
-    }
+    };
   },
 
   verifySignature: function(jws) {
+    var key;
+
     if (jws.protected) {
       if (!jws.header) {
         jws.header = {};
@@ -188,13 +190,13 @@ module.exports = {
           jws.header[key] = protectedObj[key];
         }
       } catch (e) {
-        console.log("error unmarshaling json: "+e)
+        console.log("error unmarshaling json: "+e);
         return false;
       }
     }
 
     // Assumes validSignature(sig)
-    if (!jws.header.jwk || (jws.header.jwk.kty != "RSA")) {
+    if (!jws.header.jwk || (jws.header.jwk.kty !== "RSA")) {
       // Unsupported key type
       console.log("Unsupported key type");
       return false;
@@ -240,6 +242,8 @@ module.exports = {
     csr.setSubject([{ name: 'commonName', value: names[0] }]);
 
     var sans = [];
+    var i;
+
     for (i in names) {
       sans.push({ type: 2, value: names[i] });
     }
@@ -264,7 +268,7 @@ module.exports = {
     }
 
     for (var i=0; i<csr.subject.attributes.length; ++i) {
-      if (csr.subject.attributes[i].name == "commonName") {
+      if (csr.subject.attributes[i].name === "commonName") {
         return csr.subject.attributes[i].value;
       }
     }
@@ -289,7 +293,7 @@ module.exports = {
     var publicKey = csr.publicKey;
     var commonName = null;
     for (var i=0; i<csr.subject.attributes.length; ++i) {
-      if (csr.subject.attributes[i].name == "commonName") {
+      if (csr.subject.attributes[i].name === "commonName") {
         commonName = csr.subject.attributes[i].value;
         break;
       }
@@ -320,7 +324,7 @@ module.exports = {
     cert.sign(privateKey);
 
     // Return base64-encoded DER
-    var der = forge.asn1.toDer(forge.pki.certificateToAsn1(cert));
+    der = forge.asn1.toDer(forge.pki.certificateToAsn1(cert));
     return bytesToBuffer(der);
   },