diff --git a/CHANGES b/CHANGES
index 7caed4d536..173cacd838 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+5403.	[func]		Don't set udp recv/send buffer sizes, sockets will
+			use system defaults. [GL #1713]
+
 5402.	[bug]		Enable SO_REUSEADDR on all platforms, and either
 			SO_REUSEPORT_LB on FreeBSD, or SO_REUSEPORT on Linux.
 			[GL !3365]
diff --git a/doc/arm/notes-9.17.2.xml b/doc/arm/notes-9.17.2.xml
index 407855b84a..dcfc529c95 100644
--- a/doc/arm/notes-9.17.2.xml
+++ b/doc/arm/notes-9.17.2.xml
@@ -89,6 +89,12 @@
           [GL #1674]
         </para>
       </listitem>
+      <listitem>
+        <para>
+          BIND 9 no longer sets the recv and send buffer sizes for sockets, relying
+          on system defaults instead. [GL #1713]
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
 
diff --git a/lib/isc/netmgr/udp.c b/lib/isc/netmgr/udp.c
index 8f6826ffa9..1b642b8928 100644
--- a/lib/isc/netmgr/udp.c
+++ b/lib/isc/netmgr/udp.c
@@ -167,11 +167,14 @@ isc__nm_async_udplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	if (r < 0) {
 		isc__nm_incstats(sock->mgr, sock->statsindex[STATID_BINDFAIL]);
 	}
-
+#ifdef ISC_RECV_BUFFER_SIZE
 	uv_recv_buffer_size(&sock->uv_handle.handle,
-			    &(int){ 16 * 1024 * 1024 });
+			    &(int){ ISC_RECV_BUFFER_SIZE });
+#endif
+#ifdef ISC_SEND_BUFFER_SIZE
 	uv_send_buffer_size(&sock->uv_handle.handle,
-			    &(int){ 16 * 1024 * 1024 });
+			    &(int){ ISC_SEND_BUFFER_SIZE });
+#endif
 	uv_udp_recv_start(&sock->uv_handle.udp, isc__nm_alloc_cb, udp_recv_cb);
 }
 
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index 2a749e4c99..f1cb70ff71 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -271,21 +271,13 @@ typedef isc_event_t intev_t;
 #endif /* ifndef USE_CMSG */
 #endif /* ifdef SO_TIMESTAMP */
 
-/*%
- * The size to raise the receive buffer to (from BIND 8).
- */
-#ifdef TUNE_LARGE
-#ifdef sun
-#define RCVBUFSIZE (1 * 1024 * 1024)
-#define SNDBUFSIZE (1 * 1024 * 1024)
-#else /* ifdef sun */
-#define RCVBUFSIZE (16 * 1024 * 1024)
-#define SNDBUFSIZE (16 * 1024 * 1024)
-#endif /* ifdef sun */
-#else  /* ifdef TUNE_LARGE */
-#define RCVBUFSIZE (32 * 1024)
-#define SNDBUFSIZE (32 * 1024)
-#endif /* TUNE_LARGE */
+#if defined(SO_RCVBUF) && defined(ISC_RECV_BUFFER_SIZE)
+#define SET_RCVBUF
+#endif
+
+#if defined(SO_SNDBUF) && defined(ISC_SEND_BUFFER_SIZE)
+#define SET_SNDBUF
+#endif
 
 /*%
  * Instead of calculating the cmsgbuf lengths every time we take
@@ -1942,9 +1934,9 @@ free_socket(isc__socket_t **socketp) {
 	isc_mem_put(sock->manager->mctx, sock, sizeof(*sock));
 }
 
-#ifdef SO_RCVBUF
+#if defined(SET_RCVBUF)
 static isc_once_t rcvbuf_once = ISC_ONCE_INIT;
-static int rcvbuf = RCVBUFSIZE;
+static int rcvbuf = ISC_RECV_BUFFER_SIZE;
 
 static void
 set_rcvbuf(void) {
@@ -2000,9 +1992,9 @@ cleanup:
 }
 #endif /* ifdef SO_RCVBUF */
 
-#ifdef SO_SNDBUF
+#if defined(SET_SNDBUF)
 static isc_once_t sndbuf_once = ISC_ONCE_INIT;
-static int sndbuf = SNDBUFSIZE;
+static int sndbuf = ISC_SEND_BUFFER_SIZE;
 
 static void
 set_sndbuf(void) {
@@ -2105,10 +2097,10 @@ opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
 #if defined(USE_CMSG) || defined(SO_NOSIGPIPE)
 	int on = 1;
 #endif /* if defined(USE_CMSG) || defined(SO_NOSIGPIPE) */
-#if defined(SO_RCVBUF) || defined(SO_SNDBUF)
+#if defined(SET_RCVBUF) || defined(SET_SNDBUF)
 	socklen_t optlen;
 	int size = 0;
-#endif /* if defined(SO_RCVBUF) || defined(SO_SNDBUF) */
+#endif
 
 again:
 	if (dup_socket == NULL) {
@@ -2271,7 +2263,7 @@ again:
 		set_tcp_maxseg(sock, 1280 - 20 - 40); /* 1280 - TCP - IPV6 */
 	}
 
-#if defined(USE_CMSG) || defined(SO_RCVBUF) || defined(SO_SNDBUF)
+#if defined(USE_CMSG) || defined(SET_RCVBUF) || defined(SET_SNDBUF)
 	if (sock->type == isc_sockettype_udp) {
 #if defined(USE_CMSG)
 #if defined(SO_TIMESTAMP)
@@ -2360,7 +2352,7 @@ again:
 		}
 #endif /* if defined(IP_DONTFRAG) */
 
-#if defined(SO_RCVBUF)
+#if defined(SET_RCVBUF)
 		optlen = sizeof(size);
 		if (getsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF, (void *)&size,
 			       &optlen) == 0 &&
@@ -2378,9 +2370,9 @@ again:
 						 sock->fd, rcvbuf, strbuf);
 			}
 		}
-#endif /* if defined(SO_RCVBUF) */
+#endif /* if defined(SET_RCVBUF) */
 
-#if defined(SO_SNDBUF)
+#if defined(SET_SNDBUF)
 		optlen = sizeof(size);
 		if (getsockopt(sock->fd, SOL_SOCKET, SO_SNDBUF, (void *)&size,
 			       &optlen) == 0 &&
@@ -2424,7 +2416,7 @@ again:
 				 sock->fd, strbuf);
 	}
 #endif /* ifdef IP_RECVTOS */
-#endif /* defined(USE_CMSG) || defined(SO_RCVBUF) || defined(SO_SNDBUF) */
+#endif /* defined(USE_CMSG) || defined(SET_RCVBUF) || defined(SET_SNDBUF) */
 
 setup_done:
 	inc_stats(manager->stats, sock->statsindex[STATID_OPEN]);