diff --git a/packages/editor-tools/src/AssetLoader.php b/packages/editor-tools/src/AssetLoader.php
index bd4dff5..f02ac09 100644
--- a/packages/editor-tools/src/AssetLoader.php
+++ b/packages/editor-tools/src/AssetLoader.php
@@ -38,7 +38,7 @@ public function __construct( private string $base_path = '', private string $pre
 	 */
 	public function load( string $handle ): void {
 		if ( ! file_exists( $this->get_asset_path( $handle ) ) ) {
-			if ( \WP_DEBUG ) {
+			if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
 				wp_die(
 					sprintf(
 						'Could not load asset %s from %s. Please ensure assets have been compiled.',
@@ -53,7 +53,7 @@ public function load( string $handle ): void {
 		$asset = require $this->get_asset_path( $handle ); // phpcs:ignore WordPressVIPMinimum.Files.IncludingFile.UsingVariable -- This is required.
 
 		if ( ! is_array( $asset ) ) {
-			if ( \WP_DEBUG ) {
+			if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
 				wp_die( sprintf( 'Asset %s is not valid. Please ensure assets have been compiled.', esc_html( $handle ) ) );
 			}
 			return;
@@ -129,9 +129,7 @@ protected function get_base_path(): string {
 	 * @return string
 	 */
 	protected function get_base_url(): string {
-		return str_replace(
-			WP_CONTENT_DIR,
-			WP_CONTENT_URL,
+		return plugin_dir_url(
 			$this->get_base_path()
 		);
 	}
diff --git a/packages/editor-tools/tests/TestAssetLoader.php b/packages/editor-tools/tests/TestAssetLoader.php
index 7c4715f..b45dcd8 100644
--- a/packages/editor-tools/tests/TestAssetLoader.php
+++ b/packages/editor-tools/tests/TestAssetLoader.php
@@ -27,6 +27,10 @@ public function testLoad(): void {
 			->once()
 			->andReturn( __DIR__ . '/fixtures/AssetLoader' );
 
+		\WP_Mock::userFunction( 'plugin_dir_url' )
+			->atLeast()->once()
+			->andReturn( 'http://localhost' );
+
 		\WP_Mock::userFunction( 'wp_enqueue_script' )
 			->once()
 			->with( 'box-test', \WP_Mock\Functions::type( 'string' ), array(), '1', true );
diff --git a/tests/bootstrap-phpstan.php b/tests/bootstrap-phpstan.php
index 83196a4..3c04228 100644
--- a/tests/bootstrap-phpstan.php
+++ b/tests/bootstrap-phpstan.php
@@ -7,12 +7,6 @@
 
 declare ( strict_types=1 );
 
-/**
- * Load Environment Configuration
-*/
-define( 'PROJECT_NAME', 'boxuk-base-wp-plugin' );
-define( 'WP_CONTENT_URL', 'http://localhost' );
-
 /* Load Stubs */
 $files = glob( __DIR__ . '/stubs/*.php' );
 foreach ( $files as $file ) {
diff --git a/tests/bootstrap-phpunit.php b/tests/bootstrap-phpunit.php
index 19119d7..48a16b4 100644
--- a/tests/bootstrap-phpunit.php
+++ b/tests/bootstrap-phpunit.php
@@ -11,7 +11,4 @@
 require_once $root_dir . '/vendor/autoload.php';
 
 define( 'WP_DEBUG', true );
-define( 'WP_CONTENT_DIR', $root_dir );
-define( 'WP_CONTENT_URL', 'http://localhost' );
-
 WP_Mock::bootstrap();