diff --git a/src/Adapter/AbstractAdapter.php b/src/Adapter/AbstractAdapter.php
index 174eded..a8b6c1e 100644
--- a/src/Adapter/AbstractAdapter.php
+++ b/src/Adapter/AbstractAdapter.php
@@ -223,9 +223,6 @@ public function writeBox(
                 case static::FILL_SHADE_DARK:
                     $fillChar = $charset::SHADE_DARK;
                     break;
-                case static::FILL_SHADE_LIGHT:
-                    $fillChar = $charset::SHADE_LIGHT;
-                    break;
                 case static::FILL_BLOCK:
                 default:
                     $fillChar = $charset::BLOCK;