diff --git a/pwa.php b/pwa.php
index 71f319652..851872dbd 100644
--- a/pwa.php
+++ b/pwa.php
@@ -197,12 +197,6 @@ function _pwa_check_disabled_navigation_preload() {
 /** WP_HTTPS_UI Class */
 require_once PWA_PLUGIN_DIR . '/wp-includes/class-wp-https-ui.php';
 
-/** WP_Service_Worker_Registry Interface */
-require_once PWA_PLUGIN_DIR . '/wp-includes/interface-wp-service-worker-registry.php';
-
-/** WP_Service_Worker_Registry_Aware Interface */
-require_once PWA_PLUGIN_DIR . '/wp-includes/interface-wp-service-worker-registry-aware.php';
-
 /** WP_Service_Workers Class */
 require_once PWA_PLUGIN_DIR . '/wp-includes/class-wp-service-workers.php';
 
diff --git a/wp-includes/class-wp-service-worker-scripts.php b/wp-includes/class-wp-service-worker-scripts.php
index efc5ef510..c4f3a86f1 100644
--- a/wp-includes/class-wp-service-worker-scripts.php
+++ b/wp-includes/class-wp-service-worker-scripts.php
@@ -12,11 +12,8 @@
  * @since 0.1
  *
  * @see WP_Dependencies
- *
- * @method WP_Service_Worker_Precaching_Routes precaching_routes()
- * @method WP_Service_Worker_Caching_Routes caching_routes()
  */
-class WP_Service_Worker_Scripts extends WP_Scripts implements WP_Service_Worker_Registry {
+class WP_Service_Worker_Scripts extends WP_Scripts {
 
 	/**
 	 * Service worker components.
@@ -27,30 +24,36 @@ class WP_Service_Worker_Scripts extends WP_Scripts implements WP_Service_Worker_
 	protected $components = array();
 
 	/**
-	 * Service worker component registries.
+	 * Caching routes.
 	 *
-	 * @since 0.2
-	 * @var array
+	 * @since 0.6
+	 * @var WP_Service_Worker_Caching_Routes
 	 */
-	protected $registries = array();
+	protected $caching_routes;
+
+	/**
+	 * Precaching routes.
+	 *
+	 * @since 0.6
+	 * @var WP_Service_Worker_Precaching_Routes
+	 */
+	protected $precaching_routes;
 
 	/**
 	 * Constructor.
 	 *
 	 * @since 0.2
 	 *
-	 * @param array $components Optional. Service worker components as $slug => $instance pairs.
-	 *                          Each component must implement `WP_Service_Worker_Component`.
-	 *                          Default empty array.
+	 * @param WP_Service_Worker_Caching_Routes    $caching_routes    Caching routes.
+	 * @param WP_Service_Worker_Precaching_Routes $precaching_routes Precaching routes.
+	 * @param array                               $components Optional. Service worker components as $slug => $instance pairs.
+	 *                                                        Each component must implement `WP_Service_Worker_Component`.
+	 *                                                        Default empty array.
 	 */
-	public function __construct( $components = array() ) {
-		$this->components = $components;
-		foreach ( $this->components as $slug => $instance ) {
-			if ( $instance instanceof WP_Service_Worker_Registry_Aware ) {
-				$this->registries[ $slug ] = $instance->get_registry();
-			}
-		}
-
+	public function __construct( $caching_routes, $precaching_routes, $components = array() ) {
+		$this->caching_routes    = $caching_routes;
+		$this->precaching_routes = $precaching_routes;
+		$this->components        = $components;
 		parent::__construct();
 	}
 
@@ -77,20 +80,25 @@ public function init() {
 	}
 
 	/**
-	 * Magic call method. Allows accessing component registries.
+	 * Get caching routes registry.
 	 *
-	 * @since 0.2
+	 * @since 0.6
 	 *
-	 * @param string $method Method name. Should be the identifier for a component registry.
-	 * @param array  $args   Method arguments.
-	 * @return WP_Service_Worker_Registry|null Registry instance if valid method name, otherwise null.
+	 * @return WP_Service_Worker_Caching_Routes Registry.
 	 */
-	public function __call( $method, $args ) {
-		if ( isset( $this->registries[ $method ] ) ) {
-			return $this->registries[ $method ];
-		}
+	public function caching_routes() {
+		return $this->caching_routes;
+	}
 
-		return null;
+	/**
+	 * Get precaching routes registry.
+	 *
+	 * @since 0.6
+	 *
+	 * @return WP_Service_Worker_Precaching_Routes Registry.
+	 */
+	public function precaching_routes() {
+		return $this->precaching_routes;
 	}
 
 	/**
diff --git a/wp-includes/class-wp-service-workers.php b/wp-includes/class-wp-service-workers.php
index 4e2263604..da9afe83d 100644
--- a/wp-includes/class-wp-service-workers.php
+++ b/wp-includes/class-wp-service-workers.php
@@ -13,7 +13,7 @@
  *
  * @see WP_Dependencies
  */
-class WP_Service_Workers implements WP_Service_Worker_Registry_Aware {
+class WP_Service_Workers {
 
 	/**
 	 * Param for service workers.
@@ -50,12 +50,31 @@ class WP_Service_Workers implements WP_Service_Worker_Registry_Aware {
 	 */
 	protected $scripts;
 
+	/**
+	 * Caching routes.
+	 *
+	 * @since 0.6
+	 * @var WP_Service_Worker_Caching_Routes
+	 */
+	protected $caching_routes;
+
+	/**
+	 * Precaching routes.
+	 *
+	 * @since 0.6
+	 * @var WP_Service_Worker_Precaching_Routes
+	 */
+	protected $precaching_routes;
+
 	/**
 	 * Constructor.
 	 *
 	 * Instantiates the service worker scripts registry.
 	 */
 	public function __construct() {
+		$this->precaching_routes = new WP_Service_Worker_Precaching_Routes();
+		$this->caching_routes    = new WP_Service_Worker_Caching_Routes();
+
 		$components = array(
 			'configuration'          => new WP_Service_Worker_Configuration_Component(),
 			'navigation_routing'     => new WP_Service_Worker_Navigation_Routing_Component(),
@@ -63,11 +82,11 @@ public function __construct() {
 			'theme_asset_caching'    => new WP_Service_Worker_Theme_Asset_Caching_Component(),
 			'plugin_asset_caching'   => new WP_Service_Worker_Plugin_Asset_Caching_Component(),
 			'uploaded_image_caching' => new WP_Service_Worker_Uploaded_Image_Caching_Component(),
-			'precaching_routes'      => new WP_Service_Worker_Precaching_Routes_Component(),
-			'caching_routes'         => new WP_Service_Worker_Caching_Routes_Component(),
+			'precaching_routes'      => new WP_Service_Worker_Precaching_Routes_Component( $this->precaching_routes ),
+			'caching_routes'         => new WP_Service_Worker_Caching_Routes_Component( $this->caching_routes ),
 		);
 
-		$this->scripts = new WP_Service_Worker_Scripts( $components );
+		$this->scripts = new WP_Service_Worker_Scripts( $this->caching_routes, $this->precaching_routes, $components );
 	}
 
 	/**
diff --git a/wp-includes/components/class-wp-service-worker-caching-routes-component.php b/wp-includes/components/class-wp-service-worker-caching-routes-component.php
index 60ee2df3b..cf1713333 100644
--- a/wp-includes/components/class-wp-service-worker-caching-routes-component.php
+++ b/wp-includes/components/class-wp-service-worker-caching-routes-component.php
@@ -10,7 +10,7 @@
  *
  * @since 0.2
  */
-class WP_Service_Worker_Caching_Routes_Component implements WP_Service_Worker_Component, WP_Service_Worker_Registry_Aware {
+class WP_Service_Worker_Caching_Routes_Component implements WP_Service_Worker_Component {
 
 	/**
 	 * Caching routes registry.
@@ -26,9 +26,11 @@ class WP_Service_Worker_Caching_Routes_Component implements WP_Service_Worker_Co
 	 * Instantiates the registry.
 	 *
 	 * @since 0.2
+	 *
+	 * @param WP_Service_Worker_Caching_Routes $registry Registry.
 	 */
-	public function __construct() {
-		$this->registry = new WP_Service_Worker_Caching_Routes();
+	public function __construct( WP_Service_Worker_Caching_Routes $registry ) {
+		$this->registry = $registry;
 	}
 
 	/**
@@ -59,15 +61,6 @@ public function get_priority() {
 		return 999999;
 	}
 
-	/**
-	 * Gets the registry.
-	 *
-	 * @return WP_Service_Worker_Caching_Routes Caching routes registry instance.
-	 */
-	public function get_registry() {
-		return $this->registry;
-	}
-
 	/**
 	 * Gets the script that registers the caching routes.
 	 *
diff --git a/wp-includes/components/class-wp-service-worker-caching-routes.php b/wp-includes/components/class-wp-service-worker-caching-routes.php
index 0554deebb..116f9a59a 100644
--- a/wp-includes/components/class-wp-service-worker-caching-routes.php
+++ b/wp-includes/components/class-wp-service-worker-caching-routes.php
@@ -10,7 +10,7 @@
  *
  * @since 0.2
  */
-class WP_Service_Worker_Caching_Routes implements WP_Service_Worker_Registry {
+class WP_Service_Worker_Caching_Routes {
 
 	/**
 	 * Stale while revalidate caching strategy.
@@ -79,36 +79,43 @@ class WP_Service_Worker_Caching_Routes implements WP_Service_Worker_Registry {
 	 *
 	 * @since 0.2
 	 *
-	 * @param string       $route Route regular expression, without delimiters.
-	 * @param array|string $args {
-	 *     Additional route arguments, or else just the strategy name as a string.
+	 * @param string       $route    Route regular expression, without delimiters.
+	 * @param string|array $strategy Strategy, can be WP_Service_Worker_Caching_Routes::STRATEGY_STALE_WHILE_REVALIDATE,
+	 *                               WP_Service_Worker_Caching_Routes::STRATEGY_CACHE_FIRST, WP_Service_Worker_Caching_Routes::STRATEGY_NETWORK_FIRST,
+	 *                               WP_Service_Worker_Caching_Routes::STRATEGY_CACHE_ONLY, WP_Service_Worker_Caching_Routes::STRATEGY_NETWORK_ONLY.
+	 *                               Deprecated usage: supplying strategy args as an array.
+	 * @param array        $args {
+	 *     Additional caching strategy route arguments.
 	 *
-	 *     @type string     $strategy           Strategy, can be WP_Service_Worker_Caching_Routes::STRATEGY_STALE_WHILE_REVALIDATE,
-	 *                                          WP_Service_Worker_Caching_Routes::STRATEGY_CACHE_FIRST, WP_Service_Worker_Caching_Routes::STRATEGY_NETWORK_FIRST,
-	 *                                          WP_Service_Worker_Caching_Routes::STRATEGY_CACHE_ONLY, WP_Service_Worker_Caching_Routes::STRATEGY_NETWORK_ONLY.
-	 *                                          Required.
-	 *     @type string     $cache_name         Name to use for the cache.
-	 *     @type array|null $expiration         Expiration plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-expiration.ExpirationPlugin>.
-	 *     @type array|null $broadcast_update   Broadcast update plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-broadcast-update.BroadcastUpdatePlugin>.
-	 *     @type array|null $cacheable_response Cacheable response plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-cacheable-response.CacheableResponsePlugin>.
-	 *     @type array|null $background_sync    Background sync plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-background-sync.BackgroundSyncPlugin>.
-	 *     @type array|null $plugins            Deprecated. Array of plugins with configuration. The key of each plugin in the array must match the plugin's name.
-	 *                                          This is deprecated in favor of defining the plugins in the top-level.
-	 *                                          See <https://developers.google.com/web/tools/workbox/guides/using-plugins#workbox_plugins>.
+	 *     @type string $cache_name         Name to use for the cache.
+	 *     @type array  $expiration         Expiration plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-expiration.ExpirationPlugin>.
+	 *     @type array  $broadcast_update   Broadcast update plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-broadcast-update.BroadcastUpdatePlugin>.
+	 *     @type array  $cacheable_response Cacheable response plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-cacheable-response.CacheableResponsePlugin>.
+	 *     @type array  $background_sync    Background sync plugin configuration. See <https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-background-sync.BackgroundSyncPlugin>.
+	 *     @type array  $plugins            Deprecated. Array of plugins with configuration. The key of each plugin in the array must match the plugin's name.
+	 *                                      This is deprecated in favor of defining the plugins in the top-level.
+	 *                                      See <https://developers.google.com/web/tools/workbox/guides/using-plugins#workbox_plugins>.
 	 * @return bool Whether the registration was successful.
 	 * }
 	 */
-	public function register( $route, $args = array() ) {
-		if ( is_string( $args ) ) {
-			$args = array( 'strategy' => $args );
-		} elseif ( ! is_array( $args ) ) {
+	public function register( $route, $strategy, $args = array() ) {
+
+		// In versions prior to 0.6, this argument could either be a strategy string or an array of strategy args containing the strategy name.
+		if ( is_array( $strategy ) ) {
+			$args     = $strategy;
+			$strategy = isset( $args['strategy'] ) ? $args['strategy'] : null;
+			unset( $args['strategy'] );
+		}
+
+		if ( empty( $strategy ) || ! is_string( $strategy ) ) {
 			_doing_it_wrong(
 				__METHOD__,
-				esc_html__( 'Args must either be an array or a strategy name as a string.', 'pwa' ),
+				esc_html__( 'Strategy must be supplied.', 'pwa' ),
 				'0.6'
 			);
 			return false;
 		}
+		$args['strategy'] = $strategy;
 
 		if ( empty( $route ) || ! is_string( $route ) ) {
 			_doing_it_wrong(
diff --git a/wp-includes/components/class-wp-service-worker-core-asset-caching-component.php b/wp-includes/components/class-wp-service-worker-core-asset-caching-component.php
index f26114521..bb10086fb 100644
--- a/wp-includes/components/class-wp-service-worker-core-asset-caching-component.php
+++ b/wp-includes/components/class-wp-service-worker-core-asset-caching-component.php
@@ -76,7 +76,10 @@ public function serve( WP_Service_Worker_Scripts $scripts ) {
 		$route = $config['route'];
 		unset( $config['route'] );
 
-		$scripts->caching_routes()->register( $route, $config );
+		$strategy = $config['strategy'];
+		unset( $config['strategy'] );
+
+		$scripts->caching_routes()->register( $route, $strategy, $config );
 	}
 
 	/**
diff --git a/wp-includes/components/class-wp-service-worker-plugin-asset-caching-component.php b/wp-includes/components/class-wp-service-worker-plugin-asset-caching-component.php
index d5e3e7f99..61de4ae1b 100644
--- a/wp-includes/components/class-wp-service-worker-plugin-asset-caching-component.php
+++ b/wp-includes/components/class-wp-service-worker-plugin-asset-caching-component.php
@@ -76,7 +76,10 @@ public function serve( WP_Service_Worker_Scripts $scripts ) {
 		$route = $config['route'];
 		unset( $config['route'] );
 
-		$scripts->caching_routes()->register( $route, $config );
+		$strategy = $config['strategy'];
+		unset( $config['strategy'] );
+
+		$scripts->caching_routes()->register( $route, $strategy, $config );
 	}
 
 	/**
diff --git a/wp-includes/components/class-wp-service-worker-precaching-routes-component.php b/wp-includes/components/class-wp-service-worker-precaching-routes-component.php
index 805a5cefb..f41f6a674 100644
--- a/wp-includes/components/class-wp-service-worker-precaching-routes-component.php
+++ b/wp-includes/components/class-wp-service-worker-precaching-routes-component.php
@@ -10,7 +10,7 @@
  *
  * @since 0.2
  */
-class WP_Service_Worker_Precaching_Routes_Component implements WP_Service_Worker_Component, WP_Service_Worker_Registry_Aware {
+class WP_Service_Worker_Precaching_Routes_Component implements WP_Service_Worker_Component {
 
 	/**
 	 * Precaching routes registry.
@@ -23,12 +23,12 @@ class WP_Service_Worker_Precaching_Routes_Component implements WP_Service_Worker
 	/**
 	 * Constructor.
 	 *
-	 * Instantiates the registry.
-	 *
 	 * @since 0.2
+	 *
+	 * @param WP_Service_Worker_Precaching_Routes $registry Registry.
 	 */
-	public function __construct() {
-		$this->registry = new WP_Service_Worker_Precaching_Routes();
+	public function __construct( WP_Service_Worker_Precaching_Routes $registry ) {
+		$this->registry = $registry;
 	}
 
 	/**
@@ -64,15 +64,6 @@ public function get_priority() {
 		return -99999;
 	}
 
-	/**
-	 * Gets the registry.
-	 *
-	 * @return WP_Service_Worker_Precaching_Routes Precaching routes registry instance.
-	 */
-	public function get_registry() {
-		return $this->registry;
-	}
-
 	/**
 	 * Gets the script that registers the precaching routes.
 	 *
diff --git a/wp-includes/components/class-wp-service-worker-precaching-routes.php b/wp-includes/components/class-wp-service-worker-precaching-routes.php
index 451cafcda..7c3aa11fc 100644
--- a/wp-includes/components/class-wp-service-worker-precaching-routes.php
+++ b/wp-includes/components/class-wp-service-worker-precaching-routes.php
@@ -10,7 +10,7 @@
  *
  * @since 0.2
  */
-class WP_Service_Worker_Precaching_Routes implements WP_Service_Worker_Registry {
+class WP_Service_Worker_Precaching_Routes {
 
 	/**
 	 * Registered caching routes.
diff --git a/wp-includes/components/class-wp-service-worker-theme-asset-caching-component.php b/wp-includes/components/class-wp-service-worker-theme-asset-caching-component.php
index ab2ef0185..de56ee5ab 100644
--- a/wp-includes/components/class-wp-service-worker-theme-asset-caching-component.php
+++ b/wp-includes/components/class-wp-service-worker-theme-asset-caching-component.php
@@ -43,7 +43,7 @@ public function serve( WP_Service_Worker_Scripts $scripts ) {
 			'strategy'   => WP_Service_Worker_Caching_Routes::STRATEGY_NETWORK_FIRST,
 			'cache_name' => self::CACHE_NAME,
 			'expiration' => array(
-				'maxEntries' => 34,
+				'max_entries' => 34,
 			),
 		);
 
@@ -83,7 +83,10 @@ public function serve( WP_Service_Worker_Scripts $scripts ) {
 		$route = $config['route'];
 		unset( $config['route'] );
 
-		$scripts->caching_routes()->register( $route, $config );
+		$strategy = $config['strategy'];
+		unset( $config['strategy'] );
+
+		$scripts->caching_routes()->register( $route, $strategy, $config );
 	}
 
 	/**
diff --git a/wp-includes/components/class-wp-service-worker-uploaded-image-caching-component.php b/wp-includes/components/class-wp-service-worker-uploaded-image-caching-component.php
index 56cc5d969..f203fd88c 100644
--- a/wp-includes/components/class-wp-service-worker-uploaded-image-caching-component.php
+++ b/wp-includes/components/class-wp-service-worker-uploaded-image-caching-component.php
@@ -102,7 +102,10 @@ static function ( $image_extension ) {
 		$route = $config['route'];
 		unset( $config['route'] );
 
-		$scripts->caching_routes()->register( $route, $config );
+		$strategy = $config['strategy'];
+		unset( $config['strategy'] );
+
+		$scripts->caching_routes()->register( $route, $strategy, $config );
 	}
 
 	/**
diff --git a/wp-includes/interface-wp-service-worker-registry-aware.php b/wp-includes/interface-wp-service-worker-registry-aware.php
deleted file mode 100644
index a472e8a13..000000000
--- a/wp-includes/interface-wp-service-worker-registry-aware.php
+++ /dev/null
@@ -1,21 +0,0 @@
-<?php
-/**
- * WP_Service_Worker_Registry_Aware interface.
- *
- * @package PWA
- */
-
-/**
- * Interface for classes that host a registry.
- *
- * @since 0.2
- */
-interface WP_Service_Worker_Registry_Aware {
-
-	/**
-	 * Gets the registry.
-	 *
-	 * @return WP_Service_Worker_Registry Registry instance.
-	 */
-	public function get_registry();
-}
diff --git a/wp-includes/interface-wp-service-worker-registry.php b/wp-includes/interface-wp-service-worker-registry.php
deleted file mode 100644
index bedadbcf9..000000000
--- a/wp-includes/interface-wp-service-worker-registry.php
+++ /dev/null
@@ -1,33 +0,0 @@
-<?php
-/**
- * WP_Service_Worker_Registry interface.
- *
- * @package PWA
- */
-
-/**
- * Interface representing a service worker registry.
- *
- * @since 0.2
- */
-interface WP_Service_Worker_Registry {
-
-	/**
-	 * Registers an item.
-	 *
-	 * @since 0.2
-	 *
-	 * @param string $handle Handle of the item.
-	 * @param array  $args   Optional. Additional arguments. Default empty array.
-	 */
-	public function register( $handle, $args = array() );
-
-	/**
-	 * Gets all registered items.
-	 *
-	 * @since 0.2
-	 *
-	 * @return array List of registered items.
-	 */
-	public function get_all();
-}