diff --git a/functions.php b/functions.php
index e7bbbdf..208556f 100644
--- a/functions.php
+++ b/functions.php
@@ -5,23 +5,46 @@
  */
 
 /**
- * Require Composer autoloader if installed on it's own
+ * Helper function for prettying up errors
+ * @param string $message
+ * @param string $subtitle
+ * @param string $title
  */
-if (file_exists($composer = __DIR__ . '/vendor/autoload.php')) {
-    require_once $composer;
+$error = function ($message, $subtitle = '', $title = '') {
+    $title = $title ?: __('Sage › Error', 'sage');
+    $footer = '<a href="https://roots.io/sage/docs">roots.io/sage/docs</a>';
+    $message = "<h1>{$title}<br><small>{$subtitle}</small></h1><p>{$message}</p><p>{$footer}</p>";
+    wp_die($message, $title);
+};
+
+/**
+ * Ensure compatible version of PHP is used
+ */
+if (version_compare('5.6.4', phpversion(), '>=')) {
+    $error(__('You must be using PHP 5.6.4 or greater.', 'sage'), __('Invalid PHP version', 'sage'));
 }
 
 /**
- * Sage includes
- *
- * The $sage_includes array determines the code library included in your theme.
- * Add or remove files to the array as needed. Supports child theme overrides.
- *
- * Please note that missing files will produce a fatal error.
+ * Ensure dependencies are loaded
  */
-array_map(function ($file) {
-    if (!locate_template("src/{$file}.php", true, true)) {
-        trigger_error(sprintf(__('Error locating %s for inclusion', 'sage'), $file), E_USER_ERROR);
+if (!file_exists($composer = __DIR__.'/vendor/autoload.php') && !class_exists('Roots\\Sage\\Container')) {
+    $error(
+        __('You must run <code>composer install</code> from the Sage directory.', 'sage'),
+        __('Autoloader not found.', 'sage')
+    );
+}
+require_once $composer;
+
+/**
+ * Sage required files
+ *
+ * The mapped array determines the code library included in your theme.
+ * Add or remove files to the array as needed. Supports child theme overrides.
+ */
+array_map(function ($file) use ($error) {
+    $file = "src/{$file}.php";
+    if (!locate_template($file, true, true)) {
+        $error(sprintf(__('Error locating <code>%s</code> for inclusion.', 'sage'), $file), 'File not found');
     }
 }, ['helpers', 'setup', 'filters', 'admin']);
 
diff --git a/src/admin.php b/src/admin.php
index bb25aac..ba6979a 100644
--- a/src/admin.php
+++ b/src/admin.php
@@ -8,6 +8,12 @@ namespace App;
 add_action('customize_register', function (\WP_Customize_Manager $wp_customize) {
     // Add postMessage support
     $wp_customize->get_setting('blogname')->transport = 'postMessage';
+    $wp_customize->selective_refresh->add_partial('blogname', [
+        'selector' => '.brand',
+        'render_callback' => function () {
+            bloginfo('name');
+        }
+    ]);
 });
 
 /**
diff --git a/src/filters.php b/src/filters.php
index 0539c30..da4bbe8 100644
--- a/src/filters.php
+++ b/src/filters.php
@@ -57,7 +57,7 @@ add_filter('template_include', function ($template) {
     echo template($template, $data);
 
     // Return a blank file to make WordPress happy
-    return dirname(__DIR__).'/index.php';
+    return get_theme_file_path('index.php');
 }, PHP_INT_MAX);
 
 /**
diff --git a/src/lib/Sage/Template/BladeProvider.php b/src/lib/Sage/Template/BladeProvider.php
index 40d59b4..63f3247 100644
--- a/src/lib/Sage/Template/BladeProvider.php
+++ b/src/lib/Sage/Template/BladeProvider.php
@@ -16,11 +16,12 @@ class BladeProvider extends ViewServiceProvider
     /**
      * @param ContainerContract $container
      * @param array             $config
+     * @SuppressWarnings(PHPMD.StaticAccess)
      */
     public function __construct(ContainerContract $container = null, $config = [])
     {
         /** @noinspection PhpParamsInspection */
-        parent::__construct($container ?: new Container);
+        parent::__construct($container ?: Container::getInstance());
 
         $this->app->bindIf('config', function () use ($config) {
             return $config;
@@ -45,9 +46,7 @@ class BladeProvider extends ViewServiceProvider
      */
     public function registerFilesystem()
     {
-        $this->app->bindIf('files', function () {
-            return new Filesystem;
-        }, true);
+        $this->app->bindIf('files', Filesystem::class, true);
         return $this;
     }
 
@@ -56,9 +55,7 @@ class BladeProvider extends ViewServiceProvider
      */
     public function registerEvents()
     {
-        $this->app->bindIf('events', function () {
-            return new Dispatcher;
-        }, true);
+        $this->app->bindIf('events', Dispatcher::class, true);
         return $this;
     }
 
diff --git a/src/setup.php b/src/setup.php
index fd8ab6e..e9bed02 100644
--- a/src/setup.php
+++ b/src/setup.php
@@ -56,6 +56,12 @@ add_action('after_setup_theme', function () {
      */
     add_theme_support('html5', ['caption', 'comment-form', 'comment-list', 'gallery', 'search-form']);
 
+    /**
+     * Enable selective refresh for widgets in customizer
+     * @link https://developer.wordpress.org/themes/advanced-topics/customizer-api/#theme-support-in-sidebars
+     */
+    add_theme_support('customize-selective-refresh-widgets');
+
     /**
      * Use main stylesheet for visual editor
      * @see assets/styles/layouts/_tinymce.scss