diff --git a/src/lib/api.js b/src/lib/api.js
index 2efd806b7..e7d9fc012 100644
--- a/src/lib/api.js
+++ b/src/lib/api.js
@@ -1,4 +1,5 @@
 var defaults = require('lodash.defaults');
+var defaultsDeep = require('lodash.defaultsdeep');
 var xhr = require('xhr');
 
 var jar  = require('./jar');
@@ -15,17 +16,15 @@ var urlParams = require('./url-params');
  */
 
 module.exports = function (opts, callback) {
-    defaults(opts, {
+    defaultsDeep(opts, {
         host: process.env.API_HOST,
-        headers: {},
+        headers: {
+            'X-Requested-With': 'XMLHttpRequest'
+        },
         responseType: 'json',
         useCsrf: false
     });
 
-    defaults(opts.headers, {
-        'X-Requested-With': 'XMLHttpRequest'
-    });
-
     opts.uri = opts.host + opts.uri;
 
     if (opts.params) {
@@ -43,7 +42,9 @@ module.exports = function (opts, callback) {
             // For IE < 10, we must use XDR for cross-domain requests. XDR does not support
             // custom headers.
             defaults(opts, {useXDR: true});
-            delete opts.headers;
+            if (opts.useXDR) {
+                delete opts.headers;
+            }
             if (opts.authentication) {
                 var authenticationParams = ['x-token=' + opts.authentication];
                 var parts = opts.uri.split('?');
diff --git a/src/lib/smarty-streets.js b/src/lib/smarty-streets.js
index 42400626a..87b245e23 100644
--- a/src/lib/smarty-streets.js
+++ b/src/lib/smarty-streets.js
@@ -8,7 +8,11 @@ module.exports = function smartyStreetApi (params, callback) {
     api({
         host: 'https://api.smartystreets.com',
         uri: '/street-address',
-        params: params
+        headers: {
+            'X-Standardize-Only': true
+        },
+        params: params,
+        useXDR: false
     }, function (err, body, res) {
         if (err) return callback(err);
         if (res.statusCode !== 200) {