diff --git a/language/oop5/basic.xml b/language/oop5/basic.xml
index 9071a404f20e..1a3cf5e3b9c3 100644
--- a/language/oop5/basic.xml
+++ b/language/oop5/basic.xml
@@ -14,10 +14,12 @@
    </para>
    <para>
     The class name can be any valid label, provided it is not a
-    PHP <link linkend="reserved">reserved word</link>. A valid class
-    name starts with a letter or underscore, followed by any number of
-    letters, numbers, or underscores. As a regular expression, it
-    would be expressed thus:
+    PHP <link linkend="reserved">reserved word</link>.
+    As of PHP 8.4.0, using a single underscore <literal>_</literal> as a
+    class name is deprecated.
+    A valid class name starts with a letter or underscore,
+    followed by any number of letters, numbers, or underscores.
+    As a regular expression, it would be expressed thus:
     <code>^[a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*$</code>.
    </para>
    <para>