diff --git a/reference/posix/functions/posix-times.xml b/reference/posix/functions/posix-times.xml
index 100dad2e51..53a1aa2d08 100644
--- a/reference/posix/functions/posix-times.xml
+++ b/reference/posix/functions/posix-times.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.2 $ -->
+<!-- $Revision: 1.3 $ -->
 <!-- splitted from ./en/functions/posix.xml, last change in rev 1.2 -->
   <refentry id="function.posix-times">
    <refnamediv>
@@ -34,6 +34,12 @@
        </simpara></listitem>
      </itemizedlist>
     </para>
+    <warning>
+     <para>
+      This function isn't reliable to use, it may return negative values for
+      high times.
+     </para>
+    </warning>
    </refsect1>
   </refentry>