diff --git a/features/file-upload.xml b/features/file-upload.xml
index 15bedbe3cd..e9a448f0be 100644
--- a/features/file-upload.xml
+++ b/features/file-upload.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.29 $ -->
+<!-- $Revision: 1.30 $ -->
  <chapter id="features.file-upload">
   <title>Handling file uploads</title>
 
@@ -267,6 +267,11 @@ if (is_uploaded_file($HTTP_POST_FILES['userfile'])) {
     execution may be exceeded the value. Make sure to set
     <literal>max_execution_time</literal> large enough.
    </simpara>
+   <simpara>
+    If <literal>post_max_size</literal> is set too small, large file
+    cannot be uploaded.  Make sure to set
+    <literal>post_max_size</literal> large enough.
+   </simpara>
    <simpara>
     Not validating which file you operate on may mean that users can access
     sensitive information in other directories.