diff --git a/webui/securimage/securimage.php b/webui/securimage/securimage.php
index c7a60930..fb27ae9c 100644
--- a/webui/securimage/securimage.php
+++ b/webui/securimage/securimage.php
@@ -1438,7 +1438,7 @@ class Securimage
             $length = strlen($code['display']);
 
             for($i = 0; $i < $length; ++$i) {
-                $letter    = $code['display']{$i};
+                $letter    = $code['display'][$i];
                 $letters[] = $letter;
             }
         }