diff --git a/CHANGES b/CHANGES
index 2589110ae4..6b333c5681 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3846.	[bug]		"dig +notcp ixfr=<serial>" should result in a UDP
+			ixfr query. [RT #35980]
+
 3845.	[placeholder]
 
 3844.	[bug]		Use the x64 version of the Microsoft Visual C++
diff --git a/bin/dig/dig.c b/bin/dig/dig.c
index 295f366262..46775d8e37 100644
--- a/bin/dig/dig.c
+++ b/bin/dig/dig.c
@@ -1231,8 +1231,10 @@ plus_option(char *option, isc_boolean_t is_batchfile,
 		switch (cmd[1]) {
 		case 'c': /* tcp */
 			FULLCHECK("tcp");
-			if (!is_batchfile)
+			if (!is_batchfile) {
 				lookup->tcp_mode = state;
+				lookup->tcp_mode_set = ISC_TRUE;
+			}
 			break;
 		case 'i': /* timeout */
 			FULLCHECK("timeout");
@@ -1330,8 +1332,10 @@ plus_option(char *option, isc_boolean_t is_batchfile,
 		break;
 	case 'v':
 		FULLCHECK("vc");
-		if (!is_batchfile)
+		if (!is_batchfile) {
 			lookup->tcp_mode = state;
+			lookup->tcp_mode_set = ISC_TRUE;
+		}
 		break;
 	default:
 	invalid_option:
@@ -1549,7 +1553,8 @@ dash_option(char *option, char *next, dig_lookup_t **lookup,
 				(*lookup)->ixfr_serial = serial;
 				(*lookup)->section_question = plusquest;
 				(*lookup)->comments = pluscomm;
-				(*lookup)->tcp_mode = ISC_TRUE;
+				if (!(*lookup)->tcp_mode_set)
+					(*lookup)->tcp_mode = ISC_TRUE;
 			} else {
 				(*lookup)->rdtype = rdtype;
 				(*lookup)->rdtypeset = ISC_TRUE;
@@ -1815,7 +1820,8 @@ parse_args(isc_boolean_t is_batchfile, isc_boolean_t config_only,
 						lookup->section_question =
 							plusquest;
 						lookup->comments = pluscomm;
-						lookup->tcp_mode = ISC_TRUE;
+						if (!lookup->tcp_mode_set)
+							lookup->tcp_mode = ISC_TRUE;
 					} else {
 						lookup->rdtype = rdtype;
 						lookup->rdtypeset = ISC_TRUE;
diff --git a/bin/dig/dig.docbook b/bin/dig/dig.docbook
index 8af7873338..c3e32b95bf 100644
--- a/bin/dig/dig.docbook
+++ b/bin/dig/dig.docbook
@@ -366,10 +366,11 @@
           <term><option>+[no]tcp</option></term>
           <listitem>
             <para>
-              Use [do not use] TCP when querying name servers.  The default
-              behavior is to use UDP unless an AXFR or IXFR query is
-              requested, in
-              which case a TCP connection is used.
+              Use [do not use] TCP when querying name servers. The
+              default behavior is to use UDP unless
+              an <literal>ixfr=N</literal> query is requested, in
+              which case the default is TCP.
+              AXFR queries always use TCP.
             </para>
           </listitem>
         </varlistentry>
diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 3b26fb30e8..d4a13d737a 100644
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -796,6 +796,7 @@ make_empty_lookup(void) {
 	looknew->retries = tries;
 	looknew->nsfound = 0;
 	looknew->tcp_mode = ISC_FALSE;
+	looknew->tcp_mode_set = ISC_FALSE;
 	looknew->ip6_int = ISC_FALSE;
 	looknew->comments = ISC_TRUE;
 	looknew->stats = ISC_TRUE;
@@ -886,6 +887,7 @@ clone_lookup(dig_lookup_t *lookold, isc_boolean_t servers) {
 	looknew->cdflag = lookold->cdflag;
 	looknew->ns_search_only = lookold->ns_search_only;
 	looknew->tcp_mode = lookold->tcp_mode;
+	looknew->tcp_mode_set = lookold->tcp_mode_set;
 	looknew->comments = lookold->comments;
 	looknew->stats = lookold->stats;
 	looknew->section_question = lookold->section_question;
diff --git a/bin/dig/include/dig/dig.h b/bin/dig/include/dig/dig.h
index 5a95890669..aeab0e5dfa 100644
--- a/bin/dig/include/dig/dig.h
+++ b/bin/dig/include/dig/dig.h
@@ -117,6 +117,7 @@ struct dig_lookup {
 		trace, /*% dig +trace */
 		trace_root, /*% initial query for either +trace or +nssearch */
 		tcp_mode,
+		tcp_mode_set,
 		ip6_int,
 		comments,
 		stats,
diff --git a/bin/tests/system/ixfr/clean.sh b/bin/tests/system/ixfr/clean.sh
index 9651efddb0..22eccfdbba 100644
--- a/bin/tests/system/ixfr/clean.sh
+++ b/bin/tests/system/ixfr/clean.sh
@@ -21,5 +21,5 @@ rm -f ns1/named.conf ns1/myftp.db
 rm -f ns3/*.jnl ns3/mytest.db ns3/subtest.db
 rm -f ns4/*.jnl ns4/*.db
 rm -f */named.memstats
-rm -f dig.out
+rm -f dig.out dig.out1 dig.out2 dig.out3
 rm -f ns3/large.db
diff --git a/bin/tests/system/ixfr/tests.sh b/bin/tests/system/ixfr/tests.sh
index c4e1bf5450..90baccbd8e 100644
--- a/bin/tests/system/ixfr/tests.sh
+++ b/bin/tests/system/ixfr/tests.sh
@@ -249,5 +249,21 @@ test ${lines:-0} -eq 2 || { echo "I:failed"; status=1; }
 messages=`sed -n 's/^;;.*messages \([0-9]*\),.*/\1/p' dig.out`
 test ${messages:-0} -gt 1 || { echo "I:failed"; status=1; }
 
+echo "I:test 'dig +notcp ixfr=<value>' vs 'dig ixfr=<value> +notcp' vs 'dig ixfr=<value>'"
+ret=0
+# Should be "switch to TCP" response
+$DIG +notcp ixfr=1 test -p 5300 @10.53.0.4 > dig.out1 || ret=1
+$DIG ixfr=1 +notcp test -p 5300 @10.53.0.4 > dig.out2 || ret=1
+$PERL ../digcomp.pl dig.out1 dig.out2 || ret=1
+awk '$4 == "SOA" { soacnt++} END {exit(soacnt == 1 ? 0 : 1);}' dig.out1 || ret=1
+awk '$4 == "SOA" { exit($7 == 4 ? 0 : 1);}' dig.out1 || ret=1
+# Should be incremental transfer.
+$DIG ixfr=1 test -p 5300 @10.53.0.4 > dig.out3 || ret=1
+awk '$4 == "SOA" { soacnt++} END {exit(soacnt == 6 ? 0 : 1);}' dig.out3 || ret=1
+if [ ${ret} != 0 ]; then
+	echo "I:failed";
+	status=1;
+fi
+
 echo "I:exit status: $status"
 exit $status