diff --git a/spec.md b/spec.md
index 50fc26e..7c82de6 100644
--- a/spec.md
+++ b/spec.md
@@ -1559,6 +1559,18 @@ $instance = new class ($a) extends \Foo implements
 };
 ```
 
+If an anonymous class has attributes, they MUST be placed starting on the next line after the `new` keyword, indented
+once, and otherwise follow the same rules as other attributes specified in section 12. The remaining anonymous class 
+declaration after the final attribute MUST start on a new line and keep the same indentation as the attributes:
+
+```php
+$example = new
+    #[Attribute]
+    class {
+        ...
+    };
+```
+
 ## 9. Enumerations
 
 Enumerations (enums) MUST follow the same guidelines as classes, except where otherwise noted below.