diff --git a/prepare.php b/prepare.php
index 2948b70..6a49999 100644
--- a/prepare.php
+++ b/prepare.php
@@ -338,7 +338,7 @@ function curl_selected_bits(\$k) { return in_array(\$k, array('version', 'ssl_ve
 	) );
 
 	// Update the command to use the downloaded Composer phar file.
-	$composer_cmd .= 'php composer.phar ';
+	$composer_cmd .= $WPT_PHP_EXECUTABLE . ' composer.phar ';
 }
 
 // Set the PHP version for Composer to ensure compatibility and update dependencies.