diff --git a/src/Exceptions/ArrayDataException.php b/src/Exceptions/ArrayDataException.php
index 79cc06c..7d48069 100644
--- a/src/Exceptions/ArrayDataException.php
+++ b/src/Exceptions/ArrayDataException.php
@@ -7,6 +7,6 @@
 /**
  * Base runtime exception type thrown by this library.
  */
-class ArrayDataException extends RuntimeException
+final class ArrayDataException extends RuntimeException
 {
 }