diff --git a/doc/src/sgml/xaggr.sgml b/doc/src/sgml/xaggr.sgml
index dce8d8f1caa..15ef46cc1e7 100644
--- a/doc/src/sgml/xaggr.sgml
+++ b/doc/src/sgml/xaggr.sgml
@@ -106,7 +106,7 @@ CREATE AGGREGATE avg (float8)
     sfunc = float8_accum,
     stype = float8[],
     finalfunc = float8_avg,
-    initcond = '{0,0}'
+    initcond = '{0,0,0}'
 );
 </programlisting>
   </para>