diff --git a/EmailValidator/EmailLexer.php b/EmailValidator/EmailLexer.php
index 4c01045..cb47c01 100644
--- a/EmailValidator/EmailLexer.php
+++ b/EmailValidator/EmailLexer.php
@@ -94,6 +94,13 @@ class EmailLexer extends AbstractLexer
      */
     public $token;
 
+    /**
+     * The next token in the input.
+     *
+     * @var array|null
+     */
+    public $lookahead;
+
     /**
      * @psalm-var array{value:'', type:null, position:0}
      */
@@ -106,6 +113,7 @@ class EmailLexer extends AbstractLexer
     public function __construct()
     {
         $this->previous = $this->token = self::$nullToken;
+        $this->lookahead = null;
     }
 
     /**