diff --git a/appendices/migration5.xml b/appendices/migration5.xml
index 2e11765817..92f849cf1d 100755
--- a/appendices/migration5.xml
+++ b/appendices/migration5.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.49 $ -->
+<!-- $Revision: 1.50 $ -->
  <appendix id="migration5">
   <title>Migrating from PHP 4 to PHP 5</title>
 
@@ -95,7 +95,10 @@
     </listitem>
     <listitem>
      <simpara>
-      You should always define your classes prior to use.
+      In some cases classes must be declared before use. It only happens if
+      some of the new features of PHP 5 (such as <link
+      linkend="language.oop5.interfaces">interfaces</link>) are used.
+      Otherwise the behaviour is the old.
      </simpara>
     </listitem>
     <listitem>
diff --git a/language/oop5/basic.xml b/language/oop5/basic.xml
index 7d8033353f..c9ed397de8 100644
--- a/language/oop5/basic.xml
+++ b/language/oop5/basic.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.18 $ -->
+<!-- $Revision: 1.19 $ -->
 
  <sect1 id="language.oop5.basic">
   <title>The Basics</title>
@@ -131,7 +131,9 @@ EOD;
     assigned to a variable.  An object will always be assigned when
     creating a new object unless the object has a
     <link linkend="language.oop5.decon">constructor</link> defined that throws an
-    <link linkend="language.exceptions">exception</link> on error.
+    <link linkend="language.exceptions">exception</link> on error. Classes
+    should be defined before instantiation (and in some cases this is a
+    requirement).
    </para>
    <example>
     <title>Creating an instance</title>