diff --git a/ext/pgsql/config.m4 b/ext/pgsql/config.m4
index 5793362ebd0..8cb85b67b85 100644
--- a/ext/pgsql/config.m4
+++ b/ext/pgsql/config.m4
@@ -59,6 +59,7 @@ if test "$PHP_PGSQL" != "no"; then
   AC_CHECK_LIB(pq, PQclientEncoding,AC_DEFINE(HAVE_PQCLIENTENCODING,1,[PostgreSQL 7.0.x or later]))
   AC_CHECK_LIB(pq, PQparameterStatus,AC_DEFINE(HAVE_PQPARAMETERSTATUS,1,[PostgreSQL 7.4 or later]))
   AC_CHECK_LIB(pq, PQprotocolVersion,AC_DEFINE(HAVE_PQPROTOCOLVERSION,1,[PostgreSQL 7.4 or later]))
+  AC_CHECK_LIB(pq, PQtransactionStatus,AC_DEFINE(HAVE_PGTRANSACTIONSTATUS,1,[PostgreSQL 7.4 or later]))
   AC_CHECK_LIB(pq, pg_encoding_to_char,AC_DEFINE(HAVE_PGSQL_WITH_MULTIBYTE_SUPPORT,1,[Whether libpq is compiled with --enable-multibye]))
   LIBS=$old_LIBS
   LDFLAGS=$old_LDFLAGS