diff --git a/contrib/pg_upgrade/server.c b/contrib/pg_upgrade/server.c
index ed67759..f2e4d63 100644
*** a/contrib/pg_upgrade/server.c
--- b/contrib/pg_upgrade/server.c
*************** check_pghost_envvar(void)
*** 300,306 ****
  	/* Get valid libpq env vars from the PQconndefaults function */
  
  	start = PQconndefaults();
! 
  	for (option = start; option->keyword != NULL; option++)
  	{
  		if (option->envvar && (strcmp(option->envvar, "PGHOST") == 0 ||
--- 300,309 ----
  	/* Get valid libpq env vars from the PQconndefaults function */
  
  	start = PQconndefaults();
! 	if (start == NULL)
! 	{
! 		pg_log(PG_FATAL,"can not get default connection options\n");
! 	}
  	for (option = start; option->keyword != NULL; option++)
  	{
  		if (option->envvar && (strcmp(option->envvar, "PGHOST") == 0 ||