diff --git a/src/display.sh b/src/display.sh
index d1ab516..abe7509 100644
--- a/src/display.sh
+++ b/src/display.sh
@@ -3,11 +3,13 @@ set -Eeuo pipefail
 
 # Docker environment variables
 
+: "${VGA:=""}"              # VGA adaptor
 : "${DISPLAY:="web"}"       # Display type
-: "${VGA:="virtio-gpu"}"    # VGA adaptor
 
 if [[ "${BOOT_MODE,,}" == "windows" ]]; then
-  [[ "$VGA" == "virtio-gpu" ]] && VGA="ramfb"
+  [ -z "$VGA" ] && VGA="ramfb"
+else
+  [ -z "$VGA" ] && VGA="virtio-gpu"
 fi
 
 case "${DISPLAY,,}" in
diff --git a/src/proc.sh b/src/proc.sh
index f1b185c..34d77bc 100644
--- a/src/proc.sh
+++ b/src/proc.sh
@@ -35,7 +35,7 @@ if [[ "$KVM" != [Nn]* ]]; then
 
   WIN_FEATURES=""
   CPU_FEATURES="kvm=on"
-  KVM_OPTS=",accel=kvm -enable-kvm"
+  KVM_OPTS=",accel=kvm -enable-kvm -global kvm-pit.lost_tick_policy=discard"
 
   #CPU_FEATURES="kvm=on,l3-cache=on"
   #WIN_FEATURES="+hypervisor,+invtsc,hv_passthrough"