diff --git a/doc/src/sgml/history.sgml b/doc/src/sgml/history.sgml
index 5273c47580..c867a10d17 100644
--- a/doc/src/sgml/history.sgml
+++ b/doc/src/sgml/history.sgml
@@ -12,7 +12,7 @@
   The object-relational database management system now known as
   <productname>PostgreSQL</productname> is derived from the
   <productname>POSTGRES</productname> package written at the
-  University of California at Berkeley.  With over two decades of
+  University of California at Berkeley.  With over three decades of
   development behind it, <productname>PostgreSQL</productname> is now
   the most advanced open-source database available anywhere.
  </para>