diff --git a/CHANGES b/CHANGES
index 407659b554..fda8d47666 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3655.	[cleanup]	Simplify TCP message processing when requesting a
+			zone transfer.  [RT #34825]
+
 3654.	[bug]		Address race condition with manual notify requests.
 			[RT #34806]
 
diff --git a/bin/tests/bigtest/buildzones.sh b/bin/tests/bigtest/buildzones.sh
index 1ef7038afd..ac85d13d69 100644
--- a/bin/tests/bigtest/buildzones.sh
+++ b/bin/tests/bigtest/buildzones.sh
@@ -14,13 +14,14 @@
 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.
 
-TOP=$( (cd ../../.. && pwd) )
+SYSTEMTESTTOP=..
+. ../conf.sh
 
 addr=127.127.0.0
 ttl=300
-named=${TOP}/bin/named/named
-keygen=${TOP}/bin/dnssec/dnssec-keygen
-dsfromkey=${TOP}/bin/dnssec/dnssec-dsfromkey
+named=${NAMED}
+keygen=${KEYGEN}
+dsfromkey=${DSFROMKEY}
 
 nextaddr() {
 	OLDIF="$IFS"
diff --git a/lib/dns/xfrin.c b/lib/dns/xfrin.c
index 08d7121951..744f87802c 100644
--- a/lib/dns/xfrin.c
+++ b/lib/dns/xfrin.c
@@ -221,7 +221,6 @@ static isc_result_t xfrin_start(dns_xfrin_ctx_t *xfr);
 static void xfrin_connect_done(isc_task_t *task, isc_event_t *event);
 static isc_result_t xfrin_send_request(dns_xfrin_ctx_t *xfr);
 static void xfrin_send_done(isc_task_t *task, isc_event_t *event);
-static void xfrin_sendlen_done(isc_task_t *task, isc_event_t *event);
 static void xfrin_recv_done(isc_task_t *task, isc_event_t *event);
 static void xfrin_timeout(isc_task_t *task, isc_event_t *event);
 
@@ -881,8 +880,11 @@ xfrin_create(isc_mem_t *mctx,
 	xfr->sourceaddr = *sourceaddr;
 	isc_sockaddr_setport(&xfr->sourceaddr, 0);
 
-	isc_buffer_init(&xfr->qbuffer, xfr->qbuffer_data,
-			sizeof(xfr->qbuffer_data));
+	/*
+	 * Reserve 2 bytes for TCP length at the begining of the buffer.
+	 */
+	isc_buffer_init(&xfr->qbuffer, &xfr->qbuffer_data[2],
+			sizeof(xfr->qbuffer_data) - 2);
 
 	xfr->magic = XFRIN_MAGIC;
 	*xfrp = xfr;
@@ -1065,10 +1067,8 @@ static isc_result_t
 xfrin_send_request(dns_xfrin_ctx_t *xfr) {
 	isc_result_t result;
 	isc_region_t region;
-	isc_region_t lregion;
 	dns_rdataset_t *qrdataset = NULL;
 	dns_message_t *msg = NULL;
-	unsigned char length[2];
 	dns_difftuple_t *soatuple = NULL;
 	dns_name_t *qname = NULL;
 	dns_dbversion_t *ver = NULL;
@@ -1137,12 +1137,16 @@ xfrin_send_request(dns_xfrin_ctx_t *xfr) {
 	isc_buffer_usedregion(&xfr->qbuffer, &region);
 	INSIST(region.length <= 65535);
 
-	length[0] = region.length >> 8;
-	length[1] = region.length & 0xFF;
-	lregion.base = length;
-	lregion.length = 2;
-	CHECK(isc_socket_send(xfr->socket, &lregion, xfr->task,
-			      xfrin_sendlen_done, xfr));
+	/*
+	 * Record message length and adjust region to include TCP
+	 * length field.
+	 */
+	xfr->qbuffer_data[0] = (region.length >> 8) & 0xff;
+	xfr->qbuffer_data[1] = region.length & 0xff;
+	region.base -= 2;
+	region.length += 2;
+	CHECK(isc_socket_send(xfr->socket, &region, xfr->task,
+			      xfrin_send_done, xfr));
 	xfr->sends++;
 
  failure:
@@ -1159,42 +1163,6 @@ xfrin_send_request(dns_xfrin_ctx_t *xfr) {
 	return (result);
 }
 
-/* XXX there should be library support for sending DNS TCP messages */
-
-static void
-xfrin_sendlen_done(isc_task_t *task, isc_event_t *event) {
-	isc_socketevent_t *sev = (isc_socketevent_t *) event;
-	dns_xfrin_ctx_t *xfr = (dns_xfrin_ctx_t *) event->ev_arg;
-	isc_result_t evresult = sev->result;
-	isc_result_t result;
-	isc_region_t region;
-
-	REQUIRE(VALID_XFRIN(xfr));
-
-	UNUSED(task);
-
-	INSIST(event->ev_type == ISC_SOCKEVENT_SENDDONE);
-	isc_event_free(&event);
-
-	xfr->sends--;
-	if (xfr->shuttingdown) {
-		maybe_free(xfr);
-		return;
-	}
-
-	xfrin_log(xfr, ISC_LOG_DEBUG(3), "sent request length prefix");
-	CHECK(evresult);
-
-	isc_buffer_usedregion(&xfr->qbuffer, &region);
-	CHECK(isc_socket_send(xfr->socket, &region, xfr->task,
-			      xfrin_send_done, xfr));
-	xfr->sends++;
- failure:
-	if (result != ISC_R_SUCCESS)
-		xfrin_fail(xfr, result, "failed sending request length prefix");
-}
-
-
 static void
 xfrin_send_done(isc_task_t *task, isc_event_t *event) {
 	isc_socketevent_t *sev = (isc_socketevent_t *) event;