diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index 261e9be..c62f7e9 100644
*** a/src/backend/libpq/pqcomm.c
--- b/src/backend/libpq/pqcomm.c
*************** pq_setkeepaliveswin32(Port *port, int id
*** 1676,1682 ****
  int
  pq_getkeepalivesidle(Port *port)
  {
! #if defined(TCP_KEEPIDLE) || defined(TCP_KEEPALIVE) || defined(WIN32)
  	if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
  		return 0;
  
--- 1676,1682 ----
  int
  pq_getkeepalivesidle(Port *port)
  {
! #if defined(TCP_KEEPIDLE) || defined(TCP_KEEPALIVE_THRESHOLD) || defined(TCP_KEEPALIVE) || defined(WIN32)
  	if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
  		return 0;
  
*************** pq_getkeepalivesidle(Port *port)
*** 1688,1694 ****
  #ifndef WIN32
  		ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_idle);
  
! #ifdef TCP_KEEPIDLE
  		if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPIDLE,
  					   (char *) &port->default_keepalives_idle,
  					   &size) < 0)
--- 1688,1695 ----
  #ifndef WIN32
  		ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_idle);
  
! #if defined(TCP_KEEPIDLE)
! 		/* TCP_KEEPIDLE is the name of this option on Linux and *BSD */
  		if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPIDLE,
  					   (char *) &port->default_keepalives_idle,
  					   &size) < 0)
*************** pq_getkeepalivesidle(Port *port)
*** 1696,1702 ****
  			elog(LOG, "getsockopt(TCP_KEEPIDLE) failed: %m");
  			port->default_keepalives_idle = -1; /* don't know */
  		}
! #else
  		if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE,
  					   (char *) &port->default_keepalives_idle,
  					   &size) < 0)
--- 1697,1713 ----
  			elog(LOG, "getsockopt(TCP_KEEPIDLE) failed: %m");
  			port->default_keepalives_idle = -1; /* don't know */
  		}
! #elif defined(TCP_KEEPALIVE_THRESHOLD)
! 		/* TCP_KEEPALIVE_THRESHOLD is the name of this option on Solaris */
! 		if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE_THRESHOLD,
! 					   (char *) &port->default_keepalives_idle,
! 					   &size) < 0)
! 		{
! 			elog(LOG, "getsockopt(TCP_KEEPALIVE_THRESHOLD) failed: %m");
! 			port->default_keepalives_idle = -1; /* don't know */
! 		}
! #else							/* must have TCP_KEEPALIVE */
! 		/* TCP_KEEPALIVE is the name of this option on macOS */
  		if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE,
  					   (char *) &port->default_keepalives_idle,
  					   &size) < 0)
*************** pq_getkeepalivesidle(Port *port)
*** 1704,1710 ****
  			elog(LOG, "getsockopt(TCP_KEEPALIVE) failed: %m");
  			port->default_keepalives_idle = -1; /* don't know */
  		}
! #endif							/* TCP_KEEPIDLE */
  #else							/* WIN32 */
  		/* We can't get the defaults on Windows, so return "don't know" */
  		port->default_keepalives_idle = -1;
--- 1715,1721 ----
  			elog(LOG, "getsockopt(TCP_KEEPALIVE) failed: %m");
  			port->default_keepalives_idle = -1; /* don't know */
  		}
! #endif							/* KEEPIDLE/KEEPALIVE_THRESHOLD/KEEPALIVE */
  #else							/* WIN32 */
  		/* We can't get the defaults on Windows, so return "don't know" */
  		port->default_keepalives_idle = -1;
*************** pq_setkeepalivesidle(int idle, Port *por
*** 1723,1729 ****
  	if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
  		return STATUS_OK;
  
! #if defined(TCP_KEEPIDLE) || defined(TCP_KEEPALIVE) || defined(SIO_KEEPALIVE_VALS)
  	if (idle == port->keepalives_idle)
  		return STATUS_OK;
  
--- 1734,1741 ----
  	if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
  		return STATUS_OK;
  
! /* check SIO_KEEPALIVE_VALS here, not just WIN32, as some toolchains lack it */
! #if defined(TCP_KEEPIDLE) || defined(TCP_KEEPALIVE_THRESHOLD) || defined(TCP_KEEPALIVE) || defined(SIO_KEEPALIVE_VALS)
  	if (idle == port->keepalives_idle)
  		return STATUS_OK;
  
*************** pq_setkeepalivesidle(int idle, Port *por
*** 1742,1755 ****
  	if (idle == 0)
  		idle = port->default_keepalives_idle;
  
! #ifdef TCP_KEEPIDLE
  	if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPIDLE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
  		elog(LOG, "setsockopt(TCP_KEEPIDLE) failed: %m");
  		return STATUS_ERROR;
  	}
! #else
  	if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
--- 1754,1777 ----
  	if (idle == 0)
  		idle = port->default_keepalives_idle;
  
! #if defined(TCP_KEEPIDLE)
! 	/* TCP_KEEPIDLE is the name of this option on Linux and *BSD */
  	if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPIDLE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
  		elog(LOG, "setsockopt(TCP_KEEPIDLE) failed: %m");
  		return STATUS_ERROR;
  	}
! #elif defined(TCP_KEEPALIVE_THRESHOLD)
! 	/* TCP_KEEPALIVE_THRESHOLD is the name of this option on Solaris */
! 	if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE_THRESHOLD,
! 				   (char *) &idle, sizeof(idle)) < 0)
! 	{
! 		elog(LOG, "setsockopt(TCP_KEEPALIVE_THRESHOLD) failed: %m");
! 		return STATUS_ERROR;
! 	}
! #else							/* must have TCP_KEEPALIVE */
! 	/* TCP_KEEPALIVE is the name of this option on macOS */
  	if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
*************** pq_setkeepalivesidle(int idle, Port *por
*** 1762,1768 ****
  #else							/* WIN32 */
  	return pq_setkeepaliveswin32(port, idle, port->keepalives_interval);
  #endif
! #else							/* TCP_KEEPIDLE || SIO_KEEPALIVE_VALS */
  	if (idle != 0)
  	{
  		elog(LOG, "setting the keepalive idle time is not supported");
--- 1784,1790 ----
  #else							/* WIN32 */
  	return pq_setkeepaliveswin32(port, idle, port->keepalives_interval);
  #endif
! #else							/* no way to set it */
  	if (idle != 0)
  	{
  		elog(LOG, "setting the keepalive idle time is not supported");
*************** pq_setkeepalivesinterval(int interval, P
*** 1812,1818 ****
  	if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
  		return STATUS_OK;
  
! #if defined(TCP_KEEPINTVL) || defined (SIO_KEEPALIVE_VALS)
  	if (interval == port->keepalives_interval)
  		return STATUS_OK;
  
--- 1834,1840 ----
  	if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
  		return STATUS_OK;
  
! #if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
  	if (interval == port->keepalives_interval)
  		return STATUS_OK;
  
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 764e960..e32c42b 100644
*** a/src/interfaces/libpq/fe-connect.c
--- b/src/interfaces/libpq/fe-connect.c
*************** setKeepalivesIdle(PGconn *conn)
*** 1470,1476 ****
  	if (idle < 0)
  		idle = 0;
  
! #ifdef TCP_KEEPIDLE
  	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPIDLE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
--- 1470,1477 ----
  	if (idle < 0)
  		idle = 0;
  
! #if defined(TCP_KEEPIDLE)
! 	/* TCP_KEEPIDLE is the name of this option on Linux and *BSD */
  	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPIDLE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
*************** setKeepalivesIdle(PGconn *conn)
*** 1481,1489 ****
  						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
  		return 0;
  	}
! #else
! #ifdef TCP_KEEPALIVE
! 	/* macOS uses TCP_KEEPALIVE rather than TCP_KEEPIDLE */
  	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPALIVE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
--- 1482,1501 ----
  						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
  		return 0;
  	}
! #elif defined(TCP_KEEPALIVE_THRESHOLD)
! 	/* TCP_KEEPALIVE_THRESHOLD is the name of this option on Solaris */
! 	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPALIVE_THRESHOLD,
! 				   (char *) &idle, sizeof(idle)) < 0)
! 	{
! 		char		sebuf[256];
! 
! 		appendPQExpBuffer(&conn->errorMessage,
! 						  libpq_gettext("setsockopt(TCP_KEEPALIVE_THRESHOLD) failed: %s\n"),
! 						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
! 		return 0;
! 	}
! #elif defined(TCP_KEEPALIVE)
! 	/* TCP_KEEPALIVE is the name of this option on macOS */
  	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPALIVE,
  				   (char *) &idle, sizeof(idle)) < 0)
  	{
*************** setKeepalivesIdle(PGconn *conn)
*** 1495,1501 ****
  		return 0;
  	}
  #endif
- #endif
  
  	return 1;
  }
--- 1507,1512 ----
*************** setKeepalivesCount(PGconn *conn)
*** 1562,1568 ****
  
  	return 1;
  }
! #else							/* Win32 */
  #ifdef SIO_KEEPALIVE_VALS
  /*
   * Enable keepalives and set the keepalive values on Win32,
--- 1573,1579 ----
  
  	return 1;
  }
! #else							/* WIN32 */
  #ifdef SIO_KEEPALIVE_VALS
  /*
   * Enable keepalives and set the keepalive values on Win32,