diff --git a/doc/src/conf.py b/doc/src/conf.py
index 9e5eac0a..7281f723 100644
--- a/doc/src/conf.py
+++ b/doc/src/conf.py
@@ -104,10 +104,10 @@ rst_epilog = """
 .. _DBAPI: http://www.python.org/dev/peps/pep-0249/
 
 .. _transaction isolation level:
-    http://www.postgresql.org/docs/8.4/static/transaction-iso.html
+    http://www.postgresql.org/docs/9.0/static/transaction-iso.html
 
 .. _serializable isolation level:
-    http://www.postgresql.org/docs/8.4/static/transaction-iso.html#XACT-SERIALIZABLE
+    http://www.postgresql.org/docs/9.0/static/transaction-iso.html#XACT-SERIALIZABLE
 
 .. _mx.DateTime: http://www.egenix.com/products/python/mxBase/mxDateTime/