diff --git a/.travis.yml b/.travis.yml
index 79016839d..44c7349e8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,52 +2,27 @@ sudo: false
 
 language: php
 
-matrix:
-  include:
-    - php: 5.3
-      env: AUTOLOAD=1
-      dist: precise
-    - php: 5.3
-      env: AUTOLOAD=0
-      dist: precise
-    - php: 5.4
-      env: AUTOLOAD=1
-    - php: 5.4
-      env: AUTOLOAD=0
-    - php: 5.5
-      env: AUTOLOAD=1
-    - php: 5.5
-      env: AUTOLOAD=0
-    - php: 5.6
-      env: AUTOLOAD=1
-    - php: 5.6
-      env: AUTOLOAD=0
-    - php: 7.0
-      env: AUTOLOAD=1
-    - php: 7.0
-      env: AUTOLOAD=0
-    - php: 7.1
-      env: AUTOLOAD=1
-    - php: 7.1
-      env: AUTOLOAD=0
-    - php: 7.2
-      env: AUTOLOAD=1
-    - php: 7.2
-      env: AUTOLOAD=0
-    - php: hhvm
-      env: AUTOLOAD=1
-    - php: hhvm
-      env: AUTOLOAD=0
+php:
+  - 5.4
+  - 5.5
+  - 5.6
+  - 7.0
+  - 7.1
+  - 7.2
+  - hhvm
+
+env:
+  global:
+    - STRIPE_MOCK_VERSION=0.5.0
+  matrix:
+    - AUTOLOAD=1
+    - AUTOLOAD=0
 
 cache:
   directories:
     - $HOME/.composer/cache/files
     - stripe-mock
 
-env:
-  global:
-    - STRIPE_MOCK_VERSION=0.5.0
-
 before_install:
   # Unpack and start stripe-mock so that the test suite can talk to it
   - |
diff --git a/README.md b/README.md
index bdc6d353c..0d18bcab8 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ You can sign up for a Stripe account at https://stripe.com.
 
 ## Requirements
 
-PHP 5.3.3 and later.
+PHP 5.4.0 and later.
 
 ## Composer
 
@@ -60,6 +60,12 @@ Please see https://stripe.com/docs/api for up-to-date documentation.
 
 ## Legacy Version Support
 
+### PHP 5.3
+
+If you are using PHP 5.3, you can download v5.8.0 ([zip](https://github.com/stripe/stripe-php/archive/v5.8.0.zip), [tar.gz](https://github.com/stripe/stripe-php/archive/v5.8.0.tar.gz)) from our [releases page](https://github.com/stripe/stripe-php/releases). This version will continue to work with new versions of the Stripe API for all common uses.
+
+### PHP 5.2
+
 If you are using PHP 5.2, you can download v1.18.0 ([zip](https://github.com/stripe/stripe-php/archive/v1.18.0.zip), [tar.gz](https://github.com/stripe/stripe-php/archive/v1.18.0.tar.gz)) from our [releases page](https://github.com/stripe/stripe-php/releases). This version will continue to work with new versions of the Stripe API for all common uses.
 
 This legacy version may be included via `require_once("/path/to/stripe-php/lib/Stripe.php");`, and used like:
diff --git a/build.php b/build.php
index 4401bb4b8..cd053e2ba 100755
--- a/build.php
+++ b/build.php
@@ -10,7 +10,7 @@
     $composer = json_decode(file_get_contents('composer.json'), true);
     unset($composer['autoload']);
     unset($composer['require-dev']['squizlabs/php_codesniffer']);
-    file_put_contents('composer.json', json_encode($composer));
+    file_put_contents('composer.json', json_encode($composer, JSON_PRETTY_PRINT));
 }
 
 passthru('composer install', $returnStatus);
diff --git a/composer.json b/composer.json
index 8cfc38a04..67473fca4 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
     }
   ],
   "require": {
-    "php": ">=5.3.3",
+    "php": ">=5.4.0",
     "ext-curl": "*",
     "ext-json": "*",
     "ext-mbstring": "*"
diff --git a/init.php b/init.php
index 8dc6406a2..e9eb3baf5 100644
--- a/init.php
+++ b/init.php
@@ -37,7 +37,6 @@
 
 // Plumbing
 require(dirname(__FILE__) . '/lib/ApiResponse.php');
-require(dirname(__FILE__) . '/lib/JsonSerializable.php');
 require(dirname(__FILE__) . '/lib/StripeObject.php');
 require(dirname(__FILE__) . '/lib/ApiRequestor.php');
 require(dirname(__FILE__) . '/lib/ApiResource.php');
diff --git a/lib/JsonSerializable.php b/lib/JsonSerializable.php
deleted file mode 100644
index 2fdf85267..000000000
--- a/lib/JsonSerializable.php
+++ /dev/null
@@ -1,18 +0,0 @@
-<?php
-
-namespace Stripe;
-
-// JsonSerializable only exists in PHP 5.4+. Stub if out if it doesn't exist
-if (interface_exists('\JsonSerializable', false)) {
-    interface JsonSerializable extends \JsonSerializable
-    {
-    }
-} else {
-    // PSR2 wants each interface to have its own file.
-    // @codingStandardsIgnoreStart
-    interface JsonSerializable
-    {
-        // @codingStandardsIgnoreEnd
-        public function jsonSerialize();
-    }
-}
diff --git a/lib/StripeObject.php b/lib/StripeObject.php
index 72e2f77b9..8ba79470e 100644
--- a/lib/StripeObject.php
+++ b/lib/StripeObject.php
@@ -2,15 +2,12 @@
 
 namespace Stripe;
 
-use ArrayAccess;
-use InvalidArgumentException;
-
 /**
  * Class StripeObject
  *
  * @package Stripe
  */
-class StripeObject implements ArrayAccess, JsonSerializable
+class StripeObject implements \ArrayAccess, \JsonSerializable
 {
     /**
      * @var Util\Set Attributes that should not be sent to the API because
@@ -105,7 +102,7 @@ public function __construct($id = null, $opts = null)
     public function __set($k, $v)
     {
         if ($v === "") {
-            throw new InvalidArgumentException(
+            throw new \InvalidArgumentException(
                 'You cannot set \''.$k.'\'to an empty string. '
                 .'We interpret empty strings as NULL in requests. '
                 .'You may set obj->'.$k.' = NULL to delete the property'
@@ -292,11 +289,7 @@ public function jsonSerialize()
 
     public function __toJSON()
     {
-        if (defined('JSON_PRETTY_PRINT')) {
-            return json_encode($this->__toArray(true), JSON_PRETTY_PRINT);
-        } else {
-            return json_encode($this->__toArray(true));
-        }
+        return json_encode($this->__toArray(true), JSON_PRETTY_PRINT);
     }
 
     public function __toString()
diff --git a/tests/Stripe/StripeObjectTest.php b/tests/Stripe/StripeObjectTest.php
index 7fcd9ab3d..87616e621 100644
--- a/tests/Stripe/StripeObjectTest.php
+++ b/tests/Stripe/StripeObjectTest.php
@@ -84,11 +84,6 @@ public function testPropertyDoesNotExists()
 
     public function testJsonEncode()
     {
-        // We can only JSON encode our objects in PHP 5.4+. 5.3 must use ->__toJSON()
-        if (version_compare(phpversion(), '5.4.0', '<')) {
-            return;
-        }
-
         $s = new StripeObject();
         $s->foo = 'a';