diff --git a/ext/pgsql/config.m4 b/ext/pgsql/config.m4
index cab47976e34..ffc416aaf4a 100644
--- a/ext/pgsql/config.m4
+++ b/ext/pgsql/config.m4
@@ -56,7 +56,7 @@ if test "$PHP_PGSQL" != "no"; then
   AC_CHECK_LIB(pq, PQsetnonblocking,AC_DEFINE(HAVE_PQSETNONBLOCKING,1,[PostgreSQL 7.0.x or laler]))
   AC_CHECK_LIB(pq, PQcmdTuples,AC_DEFINE(HAVE_PQCMDTUPLES,1,[Broken libpq under windows]))
   AC_CHECK_LIB(pq, PQoidValue,AC_DEFINE(HAVE_PQOIDVALUE,1,[Older PostgreSQL]))
-  AC_CHECK_LIB(pq, PQclientEncoding,AC_DEFINE(HAVE_PQCLIENTENCODING,1,[PostgreSQL 6.5.x or later]))
+  AC_CHECK_LIB(pq, PQclientEncoding,AC_DEFINE(HAVE_PQCLIENTENCODING,1,[PostgreSQL 7.0.x or later]))
   AC_CHECK_LIB(pq, pg_encoding_to_char,AC_DEFINE(HAVE_PGSQL_WITH_MULTIBYTE_SUPPORT,1,[Whether libpq is compiled with --enable-multibye]))
   LIBS=$old_LIBS
   LDFLAGS=$old_LDFLAGS