diff --git a/language/oop5/magic.xml b/language/oop5/magic.xml
index a01452cf53..00f85b9f9b 100644
--- a/language/oop5/magic.xml
+++ b/language/oop5/magic.xml
@@ -136,6 +136,13 @@ class Connection
     return a string, as otherwise a fatal <constant>E_RECOVERABLE_ERROR</constant>
     level error is emitted.
    </para>
+   <warning>
+    <simpara>
+     You cannot throw an exception from within a
+     <link linkend="object.tostring">__toString()</link> method. Doing so will
+     result in a fatal error.
+    </simpara>
+   </warning>
    <example>
     <title>Simple example</title>
     <programlisting role="php">