diff --git a/wp-includes/components/class-wp-service-worker-configuration-component.php b/wp-includes/components/class-wp-service-worker-configuration-component.php
index 16c1dc81e..c3c04e8ef 100644
--- a/wp-includes/components/class-wp-service-worker-configuration-component.php
+++ b/wp-includes/components/class-wp-service-worker-configuration-component.php
@@ -54,6 +54,11 @@ public function get_script() {
 		$current_scope = wp_service_workers()->get_current_scope();
 		$workbox_dir   = sprintf( 'wp-includes/js/workbox-v%s/', PWA_WORKBOX_VERSION );
 
+		$workbox_dir_url = plugins_url(
+			$workbox_dir,
+			PWA_PLUGIN_FILE
+		);
+
 		$script = '';
 		if ( SCRIPT_DEBUG ) {
 			$enable_debug_log = defined( 'WP_SERVICE_WORKER_DEBUG_LOG' ) && WP_SERVICE_WORKER_DEBUG_LOG;
@@ -64,7 +69,7 @@ public function get_script() {
 			// Load with importScripts() so that source map is available.
 			$script .= sprintf(
 				"importScripts( %s );\n",
-				wp_json_encode( PWA_PLUGIN_URL . $workbox_dir . 'workbox-sw.js' )
+				wp_json_encode( $workbox_dir_url . 'workbox-sw.js' )
 			);
 		} else {
 			// Inline the workbox-sw.js to avoid an additional HTTP request.
@@ -74,7 +79,7 @@ public function get_script() {
 
 		$options = array(
 			'debug'            => SCRIPT_DEBUG, // When true, the dev builds are loaded. Otherwise, the prod builds are used.
-			'modulePathPrefix' => PWA_PLUGIN_URL . $workbox_dir,
+			'modulePathPrefix' => $workbox_dir_url,
 		);
 		$script .= sprintf( "workbox.setConfig( %s );\n", wp_json_encode( $options ) );
 
diff --git a/wp-includes/service-workers.php b/wp-includes/service-workers.php
index 31a53ff76..04d4dddfb 100644
--- a/wp-includes/service-workers.php
+++ b/wp-includes/service-workers.php
@@ -167,11 +167,13 @@ function wp_print_service_workers() {
 		return;
 	}
 
-	$workbox_window_src = sprintf(
-		'%s/wp-includes/js/workbox-v%s/workbox-window.%s.js',
-		PWA_PLUGIN_URL,
-		PWA_WORKBOX_VERSION,
-		SCRIPT_DEBUG ? 'dev' : 'prod'
+	$workbox_window_src = plugins_url(
+		sprintf(
+			'wp-includes/js/workbox-v%s/workbox-window.%s.js',
+			PWA_WORKBOX_VERSION,
+			SCRIPT_DEBUG ? 'dev' : 'prod'
+		),
+		PWA_PLUGIN_FILE
 	);
 	$register_options   = array(
 		'scope' => $scope,