diff --git a/src/Arabic/Arabic/Glyphs.php b/src/Arabic/Arabic/Glyphs.php
index 847e325..e651c07 100644
--- a/src/Arabic/Arabic/Glyphs.php
+++ b/src/Arabic/Arabic/Glyphs.php
@@ -210,7 +210,7 @@ protected function preConvert($str)
         $output   = '';
         
         $_temp = mb_strlen($str);
-
+        $chars = [];
         for ($i = 0; $i < $_temp; $i++) {
             $chars[] = mb_substr($str, $i, 1);
         }