diff --git a/lib/utils/co.js b/lib/utils/co.js
index 9a2c28bf..2c3ab701 100644
--- a/lib/utils/co.js
+++ b/lib/utils/co.js
@@ -183,11 +183,19 @@ function cb(promise, callback) {
  */
 
 function wait() {
-  return new Promise(function(resolve, reject) {
-    nextTick(resolve);
-  });
+  return new Promise(tick);
 };
 
+/**
+ * Wait for a nextTick.
+ * @param {Function} resolve
+ * @param {Function} reject
+ */
+
+function tick(resolve, reject) {
+  nextTick(resolve);
+}
+
 /**
  * Wait for a timeout with a promise.
  * @param {Number} time
@@ -218,41 +226,6 @@ function wrap(resolve, reject) {
   };
 }
 
-/**
- * Call a function that accepts node.js
- * style callbacks, wrap with a promise.
- * @private
- * @param {Object} ctx
- * @param {Function} func
- * @param {Array} args
- * @returns {Promise}
- */
-
-function _call(ctx, func, args) {
-  return new Promise(function(resolve, reject) {
-    args.push(wrap(resolve, reject));
-    func.apply(ctx, args);
-  });
-}
-
-/**
- * Call a function that accepts node.js
- * style callbacks, wrap with a promise.
- * @param {Function} func
- * @returns {Promise}
- */
-
-function call(func) {
-  var args = new Array(Math.max(0, arguments.length - 1));
-  var i;
-
-  for (i = 1; i < arguments.length; i++)
-    args[i - 1] = arguments[i];
-
-  /* jshint validthis:true */
-  return _call(this, func, args);
-}
-
 /**
  * Wrap a function that accepts node.js
  * style callbacks into a function that
@@ -264,13 +237,17 @@ function call(func) {
 
 function promisify(func, ctx) {
   return function() {
+    var self = this;
     var args = new Array(arguments.length);
     var i;
 
     for (i = 0; i < arguments.length; i++)
       args[i] = arguments[i];
 
-    return _call(ctx || this, func, args);
+    return new Promise(function(resolve, reject) {
+      args.push(wrap(resolve, reject));
+      func.apply(ctx || self, args);
+    });
   };
 }
 
@@ -320,12 +297,12 @@ function Job(resolve, reject) {
  * This drives me nuts.
  */
 
-if (typeof window !== 'undefined') {
+if (typeof window !== 'undefined' && window) {
   window.onunhandledrejection = function(event) {
     throw event.reason;
   };
-} else {
- process.on('unhandledRejection', function(err, promise) {
+} else if (typeof process !== 'undefined' && process) {
+  process.on('unhandledRejection', function(err, promise) {
     throw err;
   });
 }
@@ -344,7 +321,6 @@ exports.cb = cb;
 exports.wait = wait;
 exports.timeout = timeout;
 exports.wrap = wrap;
-exports.call = call;
 exports.promisify = promisify;
 exports.every = every;
 exports.job = job;
diff --git a/lib/utils/util.js b/lib/utils/util.js
index c55b3946..9d80ba0e 100644
--- a/lib/utils/util.js
+++ b/lib/utils/util.js
@@ -362,7 +362,7 @@ util.isUInt32 = function isUInt32(value) {
  */
 
 util.isInt53 = function isInt53(value) {
-  return util.isSafeInteger(value) && util.isInt(value);
+  return util.isInt(value);
 };
 
 /**
@@ -372,7 +372,7 @@ util.isInt53 = function isInt53(value) {
  */
 
 util.isUInt53 = function isUInt53(value) {
-  return util.isSafeInteger(value) && util.isInt(value) && value >= 0;
+  return util.isInt(value) && value >= 0;
 };
 
 /**
@@ -579,8 +579,12 @@ util.random = function random(min, max) {
 
 util.nonce = function _nonce() {
   var nonce = new Buffer(8);
-  nonce.writeUInt32LE(util.random(0, 0x100000000), 0, true);
-  nonce.writeUInt32LE(util.random(0, 0x100000000), 4, true);
+  var a = util.random(0, 0x100000000);
+  var b = util.random(0, 0x100000000);
+
+  nonce.writeUInt32LE(a, 0, true);
+  nonce.writeUInt32LE(b, 4, true);
+
   return nonce;
 };