diff --git a/test/simulation/103-initstepslew b/test/simulation/103-initstepslew
index 163efc3..eaadf73 100755
--- a/test/simulation/103-initstepslew
+++ b/test/simulation/103-initstepslew
@@ -10,7 +10,7 @@ limit=100
 
 client_conf="initstepslew 5 192.168.123.1"
 
-min_sync_time=20
+min_sync_time=6
 max_sync_time=35
 
 for time_offset in -2.0 -0.2 0.2 2.0; do
diff --git a/test/simulation/106-refclock b/test/simulation/106-refclock
index ed04406..64844a1 100755
--- a/test/simulation/106-refclock
+++ b/test/simulation/106-refclock
@@ -6,8 +6,8 @@ test_start "SHM refclock"
 servers=0
 limit=1000
 refclock_jitter=$jitter
-min_sync_time=60
-max_sync_time=80
+min_sync_time=45
+max_sync_time=70
 client_conf="refclock SHM 0"
 
 run_test || test_fail
diff --git a/test/simulation/109-makestep b/test/simulation/109-makestep
index e74b719..40fe779 100755
--- a/test/simulation/109-makestep
+++ b/test/simulation/109-makestep
@@ -7,8 +7,8 @@ limit=200
 jitter=1e-5
 client_conf="makestep 2 1"
 
-min_sync_time=140
-max_sync_time=160
+min_sync_time=130
+max_sync_time=150
 
 for time_offset in -1.0 -0.1 0.1 1.0; do
 	run_test || test_fail
diff --git a/test/simulation/201-freqaccumulation b/test/simulation/201-freqaccumulation
index a8ba917..1398319 100755
--- a/test/simulation/201-freqaccumulation
+++ b/test/simulation/201-freqaccumulation
@@ -11,7 +11,7 @@ jitter=1e-6
 base_delay=1e-6
 wander=0.0
 
-limit=200
+limit=180
 time_max_limit=1e-5
 freq_max_limit=1e-7
 time_rms_limit=1e-5
diff --git a/test/simulation/test.common b/test/simulation/test.common
index ed5ff04..dd7ec55 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=d554f187c4d196bfc10c193143d24ce724051594
+clknetsim_revision=8a7f9e753b0548e78ef3ef750da547a54d405bde
 clknetsim_url=https://github.com/mlichvar/clknetsim/archive/$clknetsim_revision.tar.gz
 
 # Only Linux is supported