diff --git a/src/HasMoneyAttributes.php b/src/HasMoneyAttributes.php
index 3ea7b0f..dae7d4e 100644
--- a/src/HasMoneyAttributes.php
+++ b/src/HasMoneyAttributes.php
@@ -53,4 +53,6 @@ public function locale(string|Closure|null $locale = null): static
 
         return $this;
     }
+
+    abstract protected function evaluate(string|Closure|null $value): mixed;
 }