diff --git a/repos/ports/run/vbox5_ubuntu_16_04_32.run b/repos/ports/run/vbox5_ubuntu_16_04_32.run
index ae1bb2433d..22e28537b1 100644
--- a/repos/ports/run/vbox5_ubuntu_16_04_32.run
+++ b/repos/ports/run/vbox5_ubuntu_16_04_32.run
@@ -16,7 +16,8 @@ set use_ram_fs 1
 # However read initial overlay from disk
 set use_overlay_from_disk 1
 
-set use_serial 0
+set use_serial 1
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_ubuntu_16_04_64.run b/repos/ports/run/vbox5_ubuntu_16_04_64.run
index 5d4eaba7e3..d93390f18a 100644
--- a/repos/ports/run/vbox5_ubuntu_16_04_64.run
+++ b/repos/ports/run/vbox5_ubuntu_16_04_64.run
@@ -16,7 +16,8 @@ set use_ram_fs 1
 # However read initial overlay from disk
 set use_overlay_from_disk 1
 
-set use_serial 0
+set use_serial 1
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_vm_ubuntu_16_04_32.run b/repos/ports/run/vbox5_vm_ubuntu_16_04_32.run
index 85aad90d51..8f9b674ab3 100644
--- a/repos/ports/run/vbox5_vm_ubuntu_16_04_32.run
+++ b/repos/ports/run/vbox5_vm_ubuntu_16_04_32.run
@@ -24,13 +24,14 @@ set use_ram_fs 1
 # However read initial overlay from disk
 set use_overlay_from_disk 1
 
-set use_serial 0
+set use_serial 1
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
 
 set use_vms 1
-set use_cpu_load 0
+set use_cpu_load 1
 
 # use generic vbox5 VMM version
 set use_vbox5_nova 0
diff --git a/repos/ports/run/vbox5_vm_ubuntu_16_04_64.run b/repos/ports/run/vbox5_vm_ubuntu_16_04_64.run
index e7eb6b050d..3bb11ee402 100644
--- a/repos/ports/run/vbox5_vm_ubuntu_16_04_64.run
+++ b/repos/ports/run/vbox5_vm_ubuntu_16_04_64.run
@@ -16,7 +16,8 @@ set use_ram_fs 1
 # However read initial overlay from disk
 set use_overlay_from_disk 1
 
-set use_serial 0
+set use_serial 1
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_vm_win10_64.run b/repos/ports/run/vbox5_vm_win10_64.run
index d51a473918..c25d015cef 100644
--- a/repos/ports/run/vbox5_vm_win10_64.run
+++ b/repos/ports/run/vbox5_vm_win10_64.run
@@ -17,6 +17,7 @@ set use_ram_fs 1
 set use_overlay_from_disk 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_vm_win7_32.run b/repos/ports/run/vbox5_vm_win7_32.run
index 9cfc8f1116..9c2439bff5 100644
--- a/repos/ports/run/vbox5_vm_win7_32.run
+++ b/repos/ports/run/vbox5_vm_win7_32.run
@@ -17,6 +17,7 @@ set use_ram_fs 1
 set use_overlay_from_disk 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_vm_win7_64.run b/repos/ports/run/vbox5_vm_win7_64.run
index 04574c79c7..6c57ff3159 100644
--- a/repos/ports/run/vbox5_vm_win7_64.run
+++ b/repos/ports/run/vbox5_vm_win7_64.run
@@ -17,6 +17,7 @@ set use_ram_fs 1
 set use_overlay_from_disk 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_win10_64.run b/repos/ports/run/vbox5_win10_64.run
index a8bfe659e3..167ead826f 100644
--- a/repos/ports/run/vbox5_win10_64.run
+++ b/repos/ports/run/vbox5_win10_64.run
@@ -17,6 +17,7 @@ set use_ram_fs 1
 set use_overlay_from_disk 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_win7_32.run b/repos/ports/run/vbox5_win7_32.run
index 3e9babffdb..6f56486455 100644
--- a/repos/ports/run/vbox5_win7_32.run
+++ b/repos/ports/run/vbox5_win7_32.run
@@ -17,6 +17,7 @@ set use_ram_fs 1
 set use_overlay_from_disk 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_win7_64.run b/repos/ports/run/vbox5_win7_64.run
index d20d8cdcc3..bcb3f826cd 100644
--- a/repos/ports/run/vbox5_win7_64.run
+++ b/repos/ports/run/vbox5_win7_64.run
@@ -17,6 +17,7 @@ set use_ram_fs 1
 set use_overlay_from_disk 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_win7_64_multiple.run b/repos/ports/run/vbox5_win7_64_multiple.run
index e3fbc6110d..ff2b7c3519 100644
--- a/repos/ports/run/vbox5_win7_64_multiple.run
+++ b/repos/ports/run/vbox5_win7_64_multiple.run
@@ -28,6 +28,7 @@ set use_ram_fs 1
 set use_overlay_from_disk 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_win7_64_raw.run b/repos/ports/run/vbox5_win7_64_raw.run
index b710e93355..47bc574f07 100644
--- a/repos/ports/run/vbox5_win7_64_raw.run
+++ b/repos/ports/run/vbox5_win7_64_raw.run
@@ -16,6 +16,7 @@ set use_ram_fs 0
 set use_overlay_from_disk 0
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox5_win7_64_share.run b/repos/ports/run/vbox5_win7_64_share.run
index 617aa56956..b4c21d7f11 100644
--- a/repos/ports/run/vbox5_win7_64_share.run
+++ b/repos/ports/run/vbox5_win7_64_share.run
@@ -14,6 +14,7 @@ set overlay_image "overlay_${flavor}.vdi"
 set use_rumpfs 1
 
 set use_serial 0
+set use_check_result 1
 
 set use_usb [expr ![get_cmd_switch --autopilot]]
 set use_ps2 [have_spec ps2]
diff --git a/repos/ports/run/vbox_win.inc b/repos/ports/run/vbox_win.inc
index 348b1a0f36..19a7afdd6b 100644
--- a/repos/ports/run/vbox_win.inc
+++ b/repos/ports/run/vbox_win.inc
@@ -308,7 +308,11 @@ build_boot_image $boot_modules
 set wait_timeout 70
 if {[have_spec foc]} { set wait_timeout 120 }
 
-if {!$use_serial} {
+if {![info exists use_check_result]} {
+	set use_check_result 0
+}
+
+if {$use_check_result} {
 	run_genode_until {\[init -\> vbox.*].*Guest Additions capability report:.*seamless: no, hostWindowMapping: no, graphics: no} $wait_timeout
 
 	# run_genode_until forever 0 [output_spawn_id]
diff --git a/repos/ports/run/vm_ubuntu_16_04_32.vbox b/repos/ports/run/vm_ubuntu_16_04_32.vbox
index d06fffe09d..6e0ad7c5d4 100644
--- a/repos/ports/run/vm_ubuntu_16_04_32.vbox
+++ b/repos/ports/run/vm_ubuntu_16_04_32.vbox
@@ -62,7 +62,7 @@
         </Adapter>
       </Network>
       <UART>
-        <Port slot="0" enabled="false" IOBase="0x3f8" IRQ="4" hostMode="Disconnected"/>
+        <Port slot="0" enabled="true"  IOBase="0x3f8" IRQ="4" path="/dev/terminal" hostMode="HostDevice"/>
         <Port slot="1" enabled="false" IOBase="0x2f8" IRQ="3" hostMode="Disconnected"/>
       </UART>
       <LPT>
diff --git a/repos/ports/run/vm_ubuntu_16_04_64.vbox b/repos/ports/run/vm_ubuntu_16_04_64.vbox
index 78438da67e..dc27b9c0fc 100644
--- a/repos/ports/run/vm_ubuntu_16_04_64.vbox
+++ b/repos/ports/run/vm_ubuntu_16_04_64.vbox
@@ -62,7 +62,7 @@
         </Adapter>
       </Network>
       <UART>
-        <Port slot="0" enabled="false" IOBase="0x3f8" IRQ="4" hostMode="Disconnected"/>
+        <Port slot="0" enabled="true"  IOBase="0x3f8" IRQ="4" path="/dev/terminal" hostMode="HostDevice"/>
         <Port slot="1" enabled="false" IOBase="0x2f8" IRQ="3" hostMode="Disconnected"/>
       </UART>
       <LPT>