diff --git a/src/client.js b/src/client.js
index 9260bcbea..319011ab1 100644
--- a/src/client.js
+++ b/src/client.js
@@ -192,7 +192,9 @@ request.types = {
  */
 
 request.serialize = {
-  'application/x-www-form-urlencoded': qs.stringify,
+  'application/x-www-form-urlencoded': (obj) => {
+    return qs.stringify(obj, { indices: false, strictNullHandling: true });
+  },
   'application/json': safeStringify
 };
 
diff --git a/src/node/index.js b/src/node/index.js
index 75217c8bd..54806ab94 100644
--- a/src/node/index.js
+++ b/src/node/index.js
@@ -98,7 +98,9 @@ exports.protocols = {
  */
 
 exports.serialize = {
-  'application/x-www-form-urlencoded': qs.stringify,
+  'application/x-www-form-urlencoded': (obj) => {
+    return qs.stringify(obj, { indices: false, strictNullHandling: true });
+  },
   'application/json': safeStringify
 };
 
diff --git a/test/client/serialize.js b/test/client/serialize.js
index fe4ec91d8..8fdcadde5 100644
--- a/test/client/serialize.js
+++ b/test/client/serialize.js
@@ -38,6 +38,7 @@ describe('request.serializeObject()', () => {
     serialize({ '&name&': 'tj' }, '%26name%26=tj');
     serialize({ hello: '`test`' }, 'hello=%60test%60');
     serialize({ $hello: 'test' }, '$hello=test');
+    serialize({ foo: 'foo', foo: 'bar' }, 'foo=foo&foo=bar');
   });
 });