diff --git a/reference/mcrypt/functions/mcrypt-get-iv-size.xml b/reference/mcrypt/functions/mcrypt-get-iv-size.xml
index 46abe44a4a..347ed4d3a6 100644
--- a/reference/mcrypt/functions/mcrypt-get-iv-size.xml
+++ b/reference/mcrypt/functions/mcrypt-get-iv-size.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.6 $ -->
+<!-- $Revision: 1.7 $ -->
 <!-- splitted from ./en/functions/mcrypt.xml, last change in rev 1.7 -->
   <refentry id="function.mcrypt-get-iv-size">
    <refnamediv>
@@ -34,9 +34,11 @@
      constants of the name of the algorithm as string.
     </para>
     <para>
-     <parameter>mode</parameter> is one of the MCRYPT_MODE_modename
-     constants of one of "ecb", "cbc", "cfb", "ofb", "nofb" or 
-     "stream".
+     <parameter>mode</parameter> is one of the MCRYPT_MODE_modename constants
+     or one of "ecb", "cbc", "cfb", "ofb", "nofb" or "stream". The IV is
+     ignored in ECB mode as this mode does not require it.  You will need to
+     have the same IV (think: starting point) both at encryption and
+     decryption stages, otherwise your encryption will fail.
     </para>
     <para>
      <parameter>td</parameter> is the resource that is returned by