diff --git a/reference/math/functions/base-convert.xml b/reference/math/functions/base-convert.xml
index 1535dd7149..ac655d9cc1 100644
--- a/reference/math/functions/base-convert.xml
+++ b/reference/math/functions/base-convert.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.4 $ -->
+<!-- $Revision: 1.5 $ -->
 <!-- splitted from ./en/functions/math.xml, last change in rev 1.2 -->
   <refentry id="function.base-convert">
    <refnamediv>
@@ -43,6 +43,14 @@ echo base_convert($hexadecimal, 16, 2);
       </screen>
      </example>
     </para>
+    <warning>
+     <simpara>
+      <function>base_convert</function> may lose precision on large numbers
+      due to properties related to the internal "double" or "float" type used.
+      Please see the <link linkend="language.types.float">Floating point numbers</link>
+      section in the manual for more specific information and limitations.
+     </simpara>
+    </warning>
    </refsect1>
   </refentry>