diff --git a/language/oop.xml b/language/oop.xml
index 8933d5da34..9caba7a513 100644
--- a/language/oop.xml
+++ b/language/oop.xml
@@ -40,6 +40,10 @@ class Cart {
     array of articles in the cart and two functions to add and remove
     items from this cart.
    </para>
+   <note><simpara>
+   In PHP 4, only constant initializers for <literal>var</literal>
+   variables are allowed. Use constructors for non-constant initializers.
+   </simpara></note>
    <para>
     Classes are types, that is, they are blueprints for actual
     variables. You have to create a variable of the desired type with