diff --git a/language/oop5/basic.xml b/language/oop5/basic.xml
index f497db134d98..edb9b26a8cba 100644
--- a/language/oop5/basic.xml
+++ b/language/oop5/basic.xml
@@ -125,6 +125,72 @@ Stack trace:
+
+
+ Readonly classes
+
+ As of PHP 8.2.0, a class can be marked with the
+ readonly modifier.
+ Marking a class as readonly will add the
+ readonly modifier
+ to every declared property, and prevent the creation of
+ dynamic properties.
+ Moreover, it is impossible to add support for them by using the
+ AllowDynamicProperties attribute. Attempting to do so
+ will trigger a compile-time error.
+
+
+
+
+]]>
+
+
+
+
+ As neither untyped, nor static properties can be marked with the
+ readonly modifier, readonly classes cannot declare
+ them either:
+
+
+
+
+]]>
+
+
+
+]]>
+
+
+
+ A readonly class can be
+ extended
+ if, and only if, the child class is also a
+ readonly class.
+
+