diff --git a/test/simulation/105-ntpauth b/test/simulation/105-ntpauth
index 5cfdf32..4c77f10 100755
--- a/test/simulation/105-ntpauth
+++ b/test/simulation/105-ntpauth
@@ -37,13 +37,15 @@ for hash in $hashes; do
 	echo "$key" >> tmp/client.keys
 done
 
-for key in $(seq $keys); do
-	client_server_options="key $key"
-	run_test || test_fail
-	check_chronyd_exit || test_fail
-	check_source_selection || test_fail
-	check_packet_interval || test_fail
-	check_sync || test_fail
+for version in 3 4; do
+	for key in $(seq $keys); do
+		client_server_options="version $version key $key"
+		run_test || test_fail
+		check_chronyd_exit || test_fail
+		check_source_selection || test_fail
+		check_packet_interval || test_fail
+		check_sync || test_fail
+	done
 done
 
 server_conf=""