diff --git a/test/simulation/105-ntpauth b/test/simulation/105-ntpauth
index d696446..66ea2a5 100755
--- a/test/simulation/105-ntpauth
+++ b/test/simulation/105-ntpauth
@@ -27,16 +27,16 @@ server_conf=""
 
 run_test || test_fail
 check_chronyd_exit || test_fail
-# These checks must fail as the server doesn't know the key
+# This check must fail as the server doesn't know the key
 check_sync && test_fail
-check_packet_interval && test_fail
+check_packet_interval || test_fail
 
 server_conf="keyfile tmp/keys"
 client_conf=""
 
 run_test || test_fail
 check_chronyd_exit || test_fail
-# These checks must fail as the client doesn't know the key
+# This check must fail as the client doesn't know the key
 check_sync && test_fail
-check_packet_interval && test_fail
+check_packet_interval || test_fail
 test_pass
diff --git a/test/simulation/107-allowdeny b/test/simulation/107-allowdeny
index 7b16312..a87aed0 100755
--- a/test/simulation/107-allowdeny
+++ b/test/simulation/107-allowdeny
@@ -19,9 +19,9 @@ allow 192.168.124.0/24"
 do
 	run_test || test_fail
 	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
 	# These checks are expected to fail
 	check_source_selection && test_fail
-	check_packet_interval && test_fail
 	check_sync && test_fail
 done
 
diff --git a/test/simulation/112-port b/test/simulation/112-port
index 605d4d3..74777af 100755
--- a/test/simulation/112-port
+++ b/test/simulation/112-port
@@ -29,9 +29,9 @@ do
 	run_test || test_fail
 	check_chronyd_exit || test_fail
 	check_packet_port || test_fail
+	check_packet_interval || test_fail
 	# These checks are expected to fail
 	check_source_selection && test_fail
-	check_packet_interval && test_fail
 	check_sync && test_fail
 done
 
diff --git a/test/simulation/test.common b/test/simulation/test.common
index 8ed8c4b..611b31f 100644
--- a/test/simulation/test.common
+++ b/test/simulation/test.common
@@ -18,7 +18,7 @@ export PATH=../../:$PATH
 export CLKNETSIM_PATH=clknetsim
 
 # Known working clknetsim revision
-clknetsim_revision=8a7f9e753b0548e78ef3ef750da547a54d405bde
+clknetsim_revision=6647b1e11cf715676361c0fb449a23ade82947b9
 clknetsim_url=https://github.com/mlichvar/clknetsim/archive/$clknetsim_revision.tar.gz
 
 # Only Linux is supported
@@ -281,12 +281,12 @@ check_packet_interval() {
 		# incoming is not longer than outgoing for stratum 1 servers, and
 		# outgoing is not longer than incoming for clients.
 		nodes=$[$servers * $server_strata + $clients]
-		check_stat $in_interval 0.1 $limit && \
-			check_stat $out_interval 0.1 $limit && \
+		check_stat $in_interval 0.1 inf && \
+			check_stat $out_interval 0.1 inf && \
 			([ $i -gt $servers ] || \
 				check_stat $in_interval 0.0 $out_interval) && \
 			([ $i -le $[$servers * $server_strata] ] || \
-				check_stat $in_interval 0.0 $out_interval) && \
+				check_stat $out_interval 0.0 $in_interval) && \
 			test_ok || test_bad
 
 		[ $? -eq 0 ] || ret=1