diff --git a/language/control-structures.xml b/language/control-structures.xml
index 675aa4c064..2ba21145b4 100644
--- a/language/control-structures.xml
+++ b/language/control-structures.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.62 $ -->
+<!-- $Revision: 1.63 $ -->
  <chapter id="control-structures">
   <title>Control Structures</title>
 
@@ -472,10 +472,12 @@ for (expr1; expr2; expr3): statement; ...; endfor;
   <sect1 id="control-structures.foreach">
    <title><literal>foreach</literal></title>
    <para>
-    PHP 4 (not PHP 3) includes a <literal>foreach</literal> construct,
-    much like Perl and some other languages. This simply gives an easy
-    way to iterate over arrays. There are two syntaxes; the second is
-    a minor but useful extension of the first:
+    PHP 4 (not PHP 3) includes a <literal>foreach</literal> construct, much
+    like Perl and some other languages. This simply gives an easy way to
+    iterate over arrays. <literal>foreach</literal> works only on arrays, and
+    will issue an error when you try to use it on a variable with a different
+    data type or an uninitialized variables. There are two syntaxes; the
+    second is a minor but useful extension of the first:
     <informalexample>
      <programlisting>
 <![CDATA[