diff --git a/test/simulation/139-nts b/test/simulation/139-nts
index 74b8981..4ae6677 100755
--- a/test/simulation/139-nts
+++ b/test/simulation/139-nts
@@ -11,10 +11,11 @@ export CLKNETSIM_START_DATE=$(date -d 'Jan  1 00:00:00 UTC 2010' +'%s')
 
 cat > tmp/cert.cfg <<EOF
 cn = "node1.net1.clk"
+dns_name = "node1.net1.clk"
+ip_address = "192.168.123.1"
 serial = 001
 activation_date = "2010-01-01 00:00:00 UTC"
 expiration_date = "2010-01-02 00:00:00 UTC"
-#dns_name = "node1.net1.clk"
 signing_key
 encryption_key
 EOF
@@ -122,52 +123,64 @@ check_sync || test_fail
 
 export CLKNETSIM_START_DATE=$(date -d 'Jan  1 00:00:00 UTC 2010' +'%s')
 
-server_conf="
-ntsserverkey tmp/server.key
-ntsservercert tmp/server.crt
-ntsprocesses 0
-ntsrotate 0
-ntsdumpdir tmp
-ntsntpserver 192.168.123.2"
 client_conf="
 nosystemcert
 ntstrustedcerts tmp/server.crt
 ntsrefresh 500"
-client_server_conf="server node1.net1.clk $client_server_options"
 
-run_test || test_fail
-check_chronyd_exit || test_fail
-check_source_selection && test_fail
-check_sync && test_fail
+for dns in 1 0; do
+	server_conf="
+	ntsserverkey tmp/server.key
+	ntsservercert tmp/server.crt
+	ntsprocesses 0
+	ntsrotate 0
+	ntsdumpdir tmp"
 
-check_file_messages "	2	1	.*	4460	" 50 100 log.packets || test_fail
-check_file_messages "	2	2	.*	4460	" 0 0 log.packets || test_fail
-check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 6 8 || test_fail
-check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 6 8 || test_fail
+	if [ $dns != 0 ]; then
+		server_conf+="
+		ntsntpserver node2.net1.clk"
+		client_server_conf="server node1.net1.clk $client_server_options"
+	else
+		server_conf+="
+		ntsntpserver 192.168.123.2"
+		client_server_conf="server 192.168.123.1 $client_server_options"
+	fi
 
-servers=2
+	servers=1
 
-run_test || test_fail
-check_chronyd_exit || test_fail
-check_source_selection || test_fail
-check_sync || test_fail
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection && test_fail
+	check_sync && test_fail
 
-check_file_messages "	3	1	.*	4460	" 100 150 log.packets || test_fail
-check_file_messages "	3	2	.*	4460	" 0 0 log.packets || test_fail
-check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 1 1 || test_fail
-check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 0 0 || test_fail
+	check_file_messages "	2	1	.*	4460	" 50 100 log.packets || test_fail
+	check_file_messages "	2	2	.*	4460	" 0 0 log.packets || test_fail
+	check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 6 8 || test_fail
+	check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 6 8 || test_fail
 
-server_conf+="
-ntsratelimit interval 12 burst 1 leak 4"
+	servers=2
 
-client_chronyd_options="-d -d"
-run_test || test_fail
-check_chronyd_exit || test_fail
-check_source_selection && test_fail
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
 
-check_file_messages "	3	1	.*	4460	1	0	2" 25 50 log.packets || test_fail
-check_file_messages "	3	2	.*	4460	" 0 0 log.packets || test_fail
-check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 2 6 || test_fail
-check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 1 6 || test_fail
+	check_file_messages "	3	1	.*	4460	" 100 150 log.packets || test_fail
+	check_file_messages "	3	2	.*	4460	" 0 0 log.packets || test_fail
+	check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 1 1 || test_fail
+	check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 0 0 || test_fail
+
+	server_conf+="
+	ntsratelimit interval 12 burst 1 leak 4"
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection && test_fail
+
+	check_file_messages "	3	1	.*	4460	1	0	2" 25 50 log.packets || test_fail
+	check_file_messages "	3	2	.*	4460	" 0 0 log.packets || test_fail
+	check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 2 6 || test_fail
+	check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 1 6 || test_fail
+done
 
 test_pass
diff --git a/test/system/105-nts b/test/system/010-nts
similarity index 92%
rename from test/system/105-nts
rename to test/system/010-nts
index 5833b2f..ff8a5c5 100755
--- a/test/system/105-nts
+++ b/test/system/010-nts
@@ -2,19 +2,17 @@
 
 . ./test.common
 
-server_name="chrony-nts-test"
-
 check_chronyd_features NTS || test_skip "NTS support disabled"
 certtool --help &> /dev/null || test_skip "certtool missing"
-sed -i "/ $server_name\$/d" /etc/hosts && echo "$server $server_name" >> /etc/hosts || \
-	test_skip "Cannot modify /etc/hosts"
 
 check_chronyd_features PRIVDROP && user="nobody"
 
 test_start "NTS authentication"
 
 cat > $TEST_DIR/cert.cfg <<EOF
-cn = "$server_name"
+cn = "chrony-nts-test"
+dns_name = "chrony-nts-test"
+ip_address = "$server"
 serial = 001
 activation_date = "$(date -d '1 year ago' +'%Y-%m-%d') 00:00:00 UTC"
 expiration_date = "$(date -d '1 year' +'%Y-%m-%d') 00:00:00 UTC"