diff --git a/reference/filesystem/functions/is-file.xml b/reference/filesystem/functions/is-file.xml
index 4b868d4357..0d80d36216 100644
--- a/reference/filesystem/functions/is-file.xml
+++ b/reference/filesystem/functions/is-file.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.2 $ -->
+<!-- $Revision: 1.3 $ -->
 <!-- splitted from ./en/functions/filesystem.xml, last change in rev 1.2 -->
   <refentry id="function.is-file">
    <refnamediv>
@@ -19,6 +19,11 @@
      The results of this function are cached. See
      <function>clearstatcache</function> for more details.
     </para>
+    <simpara>
+     This function will not work on <link
+     linkend="features.remote-files">remote files</link>; the file to
+     be examined must be accessible via the server's filesystem.
+    </simpara>
     <para>
      See also <function>is_dir</function> and
      <function>is_link</function>.