diff --git a/src/Cli.php b/src/Cli.php
index b687e56..5f5b896 100644
--- a/src/Cli.php
+++ b/src/Cli.php
@@ -164,10 +164,10 @@ class Cli {
   /**
    * Handle command line arguments
    * @param array|null $args Command line argurment to handle (optional, default: $argv)
-   * @param bool|null $core_mode Force enable/disable EesyPHP core mode (optional, default: null)
+   * @param bool|null $core_mode Force enable/disable EesyPHP core mode (optional, default: false)
    * @return void
    */
-  public static function handle_args($args=null, $core_mode=null) {
+  public static function handle_args($args=null, $core_mode=false) {
     global $argv;
     self :: core_mode($core_mode);
     $args = is_array($args)?$args:array_slice($argv, 1);