diff --git a/lib/cloudapi2.js b/lib/cloudapi2.js
index 702ee4d..78257a8 100644
--- a/lib/cloudapi2.js
+++ b/lib/cloudapi2.js
@@ -31,7 +31,6 @@ var LOMStream = require('lomstream').LOMStream;
 var os = require('os');
 var querystring = require('querystring');
 var restifyClients = require('restify-clients');
-var sprintf = require('util').format;
 var vasync = require('vasync');
 
 var errors = require('./errors');
@@ -105,7 +104,7 @@ function CloudAPI(options) {
         options.version = '*';
     }
     if (!options.userAgent) {
-        options.userAgent = sprintf('triton/%s (%s-%s; node/%s)',
+        options.userAgent = format('triton/%s (%s-%s; node/%s)',
             VERSION, OS_ARCH, OS_PLATFORM, process.versions.node);
     }
 
@@ -140,7 +139,7 @@ CloudAPI.prototype._getAuthHeaders = function _getAuthHeaders(callback) {
             return;
         }
 
-        headers.authorization = sprintf(
+        headers.authorization = format(
             'Signature keyId="/%s/keys/%s",algorithm="%s",signature="%s"',
             self.user, sig.keyId, sig.algorithm, sig.signature);
         callback(null, headers);
@@ -294,7 +293,7 @@ CloudAPI.prototype.getNetwork = function getNetwork(id, cb) {
  * @param {Function} callback of the form `function (err, services, response)`
  */
 CloudAPI.prototype.listServices = function listServices(opts, cb) {
-    var endpoint = sprintf('/%s/services', this.user);
+    var endpoint = format('/%s/services', this.user);
     this._passThrough(endpoint, opts, cb);
 };
 
@@ -305,7 +304,7 @@ CloudAPI.prototype.listServices = function listServices(opts, cb) {
  *      `function (err, datacenters, response)`
  */
 CloudAPI.prototype.listDatacenters = function listDatacenters(opts, cb) {
-    var endpoint = sprintf('/%s/datacenters', this.user);
+    var endpoint = format('/%s/datacenters', this.user);
     this._passThrough(endpoint, opts, cb);
 };
 
@@ -317,7 +316,7 @@ CloudAPI.prototype.listDatacenters = function listDatacenters(opts, cb) {
  * @param {Function} callback of the form `function (err, account, response)`
  */
 CloudAPI.prototype.getAccount = function getAccount(opts, cb) {
-    var endpoint = sprintf('/%s', this.user);
+    var endpoint = format('/%s', this.user);
     this._passThrough(endpoint, opts, cb);
 };
 
@@ -327,7 +326,7 @@ CloudAPI.prototype.getAccount = function getAccount(opts, cb) {
  * @param {Function} callback of the form `function (err, keys, response)`
  */
 CloudAPI.prototype.listKeys = function listKeys(opts, cb) {
-    var endpoint = sprintf('/%s/keys', this.user);
+    var endpoint = format('/%s/keys', this.user);
     this._passThrough(endpoint, opts, cb);
 };
 
@@ -341,7 +340,7 @@ CloudAPI.prototype.listKeys = function listKeys(opts, cb) {
  * @param {Function} callback of the form `function (err, images, res)`
  */
 CloudAPI.prototype.listImages = function listImages(opts, cb) {
-    var endpoint = sprintf('/%s/images', this.user);
+    var endpoint = format('/%s/images', this.user);
     this._passThrough(endpoint, opts, cb);
 };
 
@@ -372,7 +371,7 @@ CloudAPI.prototype.getImage = function getImage(options, callback) {
 // ---- packages
 
 CloudAPI.prototype.listPackages = function listPackages(opts, cb) {
-    var endpoint = sprintf('/%s/packages', this.user);
+    var endpoint = format('/%s/packages', this.user);
     this._passThrough(endpoint, opts, cb);
 };
 
@@ -407,7 +406,7 @@ CloudAPI.prototype.getMachine = function getMachine(id, cb) {
     assert.uuid(id, 'id');
     assert.func(cb, 'cb');
 
-    var endpoint = sprintf('/%s/machines/%s', this.user, id);
+    var endpoint = format('/%s/machines/%s', this.user, id);
     this._request(endpoint, function (err, req, res, body) {
         cb(err, body, res);
     });
@@ -425,7 +424,7 @@ CloudAPI.prototype.deleteMachine = function deleteMachine(uuid, callback) {
     assert.func(callback, 'callback');
 
     var opts = {
-        path: sprintf('/%s/machines/%s', self.user, uuid),
+        path: format('/%s/machines/%s', self.user, uuid),
         method: 'DELETE'
     };
     this._request(opts, function (err, req, res, body) {
@@ -473,7 +472,7 @@ CloudAPI.prototype._doMachine = function _doMachine(action, uuid, callback) {
     assert.func(callback, 'callback');
 
     var opts = {
-        path: sprintf('/%s/machines/%s', self.user, uuid),
+        path: format('/%s/machines/%s', self.user, uuid),
         method: 'POST',
         data: {
             action: action
@@ -620,7 +619,7 @@ CloudAPI.prototype.machineAudit = function machineAudit(options, callback) {
     assert.string(options.id, 'options.id');
     assert.func(callback, 'callback');
 
-    var path = sprintf('/%s/machines/%s/audit', self.user, options.id);
+    var path = format('/%s/machines/%s/audit', self.user, options.id);
     // XXX This `client.get` block is duplicated. Add a convenience func for it:
     self._getAuthHeaders(function (hErr, headers) {
         if (hErr) {