diff --git a/bin/tests/system/ixfr/prereq.sh b/bin/tests/system/ixfr/prereq.sh
deleted file mode 100755
index 55d18ace17..0000000000
--- a/bin/tests/system/ixfr/prereq.sh
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
-#
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, you can obtain one at https://mozilla.org/MPL/2.0/.
-#
-# See the COPYRIGHT file distributed with this work for additional
-# information regarding copyright ownership.
-
-. ../conf.sh
-
-if [ "$(uname -s)" != "Linux" ]; then
-    echo_i "This test is currently broken on non-Linux platforms"
-    exit 255
-fi
-
-exit 0
diff --git a/bin/tests/system/xfer/prereq.sh b/bin/tests/system/xfer/prereq.sh
deleted file mode 100755
index 55d18ace17..0000000000
--- a/bin/tests/system/xfer/prereq.sh
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
-#
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, you can obtain one at https://mozilla.org/MPL/2.0/.
-#
-# See the COPYRIGHT file distributed with this work for additional
-# information regarding copyright ownership.
-
-. ../conf.sh
-
-if [ "$(uname -s)" != "Linux" ]; then
-    echo_i "This test is currently broken on non-Linux platforms"
-    exit 255
-fi
-
-exit 0
diff --git a/lib/isc/netmgr/netmgr-int.h b/lib/isc/netmgr/netmgr-int.h
index fe7fc7bd9b..4ffe61a1b8 100644
--- a/lib/isc/netmgr/netmgr-int.h
+++ b/lib/isc/netmgr/netmgr-int.h
@@ -287,6 +287,7 @@ struct isc__nm_uvreq {
 	int magic;
 	isc_nmsocket_t *sock;
 	isc_nmhandle_t *handle;
+	char tcplen[2];	      /* The TCP DNS message length */
 	uv_buf_t uvbuf;	      /* translated isc_region_t, to be
 			       * sent or received */
 	isc_sockaddr_t local; /* local address */
diff --git a/lib/isc/netmgr/tcpdns.c b/lib/isc/netmgr/tcpdns.c
index 0b976ecdc5..9d55f9412d 100644
--- a/lib/isc/netmgr/tcpdns.c
+++ b/lib/isc/netmgr/tcpdns.c
@@ -1238,6 +1238,7 @@ isc__nm_tcpdns_send(isc_nmhandle_t *handle, isc_region_t *region,
 	REQUIRE(sock->type == isc_nm_tcpdnssocket);
 
 	uvreq = isc__nm_uvreq_get(sock->mgr, sock);
+	*(uint16_t *)uvreq->tcplen = htons(region->length);
 	uvreq->uvbuf.base = (char *)region->base;
 	uvreq->uvbuf.len = region->length;
 
@@ -1300,8 +1301,7 @@ tcpdns_send_direct(isc_nmsocket_t *sock, isc__nm_uvreq_t *req) {
 	REQUIRE(sock->type == isc_nm_tcpdnssocket);
 
 	int r;
-	uint16_t len = htons(req->uvbuf.len);
-	uv_buf_t bufs[2] = { { .base = (char *)&len, .len = 2 },
+	uv_buf_t bufs[2] = { { .base = req->tcplen, .len = 2 },
 			     { .base = req->uvbuf.base,
 			       .len = req->uvbuf.len } };
 
diff --git a/util/copyrights b/util/copyrights
index 78903dea7b..bebc950682 100644
--- a/util/copyrights
+++ b/util/copyrights
@@ -505,7 +505,6 @@
 ./bin/tests/system/ixfr/ans2/startme		X	2011,2018,2019,2020
 ./bin/tests/system/ixfr/clean.sh		SH	2001,2004,2007,2011,2012,2014,2015,2016,2018,2019,2020
 ./bin/tests/system/ixfr/ixfr-stats.good		X	2019,2020
-./bin/tests/system/ixfr/prereq.sh		SH	2020
 ./bin/tests/system/ixfr/setup.sh		SH	2001,2004,2007,2011,2012,2013,2014,2016,2018,2019,2020
 ./bin/tests/system/ixfr/tests.sh		SH	2001,2004,2007,2011,2012,2014,2016,2018,2019,2020
 ./bin/tests/system/kasp/README			TXT.BRIEF	2019,2020
@@ -962,7 +961,6 @@
 ./bin/tests/system/xfer/dig2.good		X	2000,2001,2003,2004,2009,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020
 ./bin/tests/system/xfer/knowngood.mapped	X	2016,2018,2019,2020
 ./bin/tests/system/xfer/ns4/named.conf.base	X	2011,2013,2016,2018,2019,2020
-./bin/tests/system/xfer/prereq.sh		SH	2020
 ./bin/tests/system/xfer/setup.sh		SH	2001,2002,2004,2007,2011,2012,2013,2014,2015,2016,2018,2019,2020
 ./bin/tests/system/xfer/tests.sh		SH	2000,2001,2004,2005,2007,2011,2012,2013,2014,2015,2016,2018,2019,2020
 ./bin/tests/system/xferquota/clean.sh		SH	2000,2001,2004,2007,2012,2014,2015,2016,2018,2019,2020