diff --git a/_config.php b/_config.php
deleted file mode 100644
index c2f2f75..0000000
--- a/_config.php
+++ /dev/null
@@ -1,3 +0,0 @@
-<?php
-
-define('RESPONSIVE_IMAGES_DIR', dirname(__FILE__));
diff --git a/code/ResponsiveImageExtension.php b/code/ResponsiveImageExtension.php
index b66cdfb..a92d55f 100644
--- a/code/ResponsiveImageExtension.php
+++ b/code/ResponsiveImageExtension.php
@@ -88,7 +88,7 @@ public function __call($method, $args)
      */
     protected function createResponsiveSet($config, $defaultArgs, $set)
     {
-        Requirements::javascript(RESPONSIVE_IMAGES_DIR . '/javascript/picturefill/picturefill.min.js');
+        Requirements::javascript('heyday/silverstripe-responsive-images:javascript/picturefill/picturefill.min.js');
 
         if (!isset($config['arguments']) || !is_array($config['arguments'])) {
             throw new Exception("Responsive set $set does not have any arguments defined in its config.");
diff --git a/composer.json b/composer.json
index ce1d762..9ab1388 100644
--- a/composer.json
+++ b/composer.json
@@ -2,9 +2,20 @@
     "name": "heyday/silverstripe-responsive-images",
     "description": "Configure and send a series of image size options to the client without loading any resources until a media query can be executed.",
     "keywords": ["silverstripe", "responsive", "image", "picturefill"],
-    "type": "silverstripe-module",
+    "type": "silverstripe-vendormodule",
     "license": "MIT",
     "require": {
+        "silverstripe/vendor-plugin": "^1.0",
         "silverstripe/framework": "^4.0"
+    },
+    "extra": {
+        "expose": [
+            "javascript"
+        ]
+    },
+    "autoload": {
+        "psr-4": {
+            "Heyday\\ResponsiveImages\\": "code/"
+        }
     }
 }