diff --git a/composer.json b/composer.json
index 99c07dc..dd99975 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
     "name": "afragen/wp-dismiss-notice",
     "description": "Library for time dismissible WordPress admin notices.",
-    "version": "0.3.7",
+    "version": "0.3.4",
     "type": "library",
     "license": "MIT",
     "authors": [
diff --git a/wp-dismiss-notice.php b/wp-dismiss-notice.php
index ad669ef..2e19292 100644
--- a/wp-dismiss-notice.php
+++ b/wp-dismiss-notice.php
@@ -28,9 +28,6 @@ class WP_Dismiss_Notice {
 			return;
 		}
 
-		$js_url  = plugins_url( 'js/dismiss-notice.js', __FILE__, 'wp-dismiss-notice' );
-		$version = json_decode( file_get_contents( __DIR__ . '/composer.json' ) )->version;
-
 		/**
 		 * Filter composer.json vendor directory.
 		 * Some people don't use the standard vendor directory.
@@ -39,23 +36,26 @@ class WP_Dismiss_Notice {
 		 */
 		$vendor_dir       = apply_filters( 'dismiss_notice_vendor_dir', '/vendor' );
 		$composer_js_path = untrailingslashit( $vendor_dir ) . '/afragen/wp-dismiss-notice/js/dismiss-notice.js';
+		$plugin_js_url    = plugins_url( 'js/dismiss-notice.js', __FILE__, 'wp-dismiss-notice' );
 
-		$theme_js_url  = get_theme_file_uri( $composer_js_path );
-		$theme_js_file = parse_url( $theme_js_url, PHP_URL_PATH );
-
-		if ( file_exists( ABSPATH . $theme_js_file ) ) {
-			$js_url = $theme_js_url;
-		}
-
-		if ( '/vendor' !== $vendor_dir ) {
-			$js_url = home_url( $composer_js_path );
+		// Test to get correct URL for JS.
+		$response = get_transient( 'wp-dismiss-notice_jsurl' );
+		if ( ! $response || is_object( $response ) ) {
+			$response = wp_remote_head( $plugin_js_url );
+			$response = is_wp_error( $response ) ? 0 : wp_remote_retrieve_response_code( $response );
+			if ( is_int( $response ) ) {
+				set_transient( 'wp-dismiss-notice_jsurl', $response, WEEK_IN_SECONDS );
+			}
 		}
+		$js_url = ( 200 === (int) $response )
+			? $plugin_js_url
+			: get_stylesheet_directory_uri() . $composer_js_path;
 
 		wp_enqueue_script(
 			'dismissible-notices',
 			$js_url,
 			[ 'jquery', 'common' ],
-			$version,
+			false,
 			true
 		);