diff --git a/reference/filter/functions/filter-var.xml b/reference/filter/functions/filter-var.xml
index 029e5c5737..32e2efe0f0 100644
--- a/reference/filter/functions/filter-var.xml
+++ b/reference/filter/functions/filter-var.xml
@@ -32,7 +32,7 @@
      <term><parameter>filter</parameter></term>
      <listitem>
       <para>
-       ID of a filter to use.
+       ID of a filter to use (see the <xref linkend="filter.filters" /> manual page).
        Defaults to <constant>FILTER_DEFAULT</constant>.
       </para>
      </listitem>