diff --git a/packer/ansible/roles/inkscape/files/inkscape-silhouette b/packer/ansible/roles/inkscape/files/inkscape-silhouette
index 6b1d818..8afe49a 160000
--- a/packer/ansible/roles/inkscape/files/inkscape-silhouette
+++ b/packer/ansible/roles/inkscape/files/inkscape-silhouette
@@ -1 +1 @@
-Subproject commit 6b1d81884cd2df50ee78a248b8c3a219695bd38c
+Subproject commit 8afe49a2a52bb13bb2a34331e7c9625fb05529bf
diff --git a/packer/ansible/roles/inkscape/tasks/silhouette.yml b/packer/ansible/roles/inkscape/tasks/silhouette.yml
index 243de63..001291b 100644
--- a/packer/ansible/roles/inkscape/tasks/silhouette.yml
+++ b/packer/ansible/roles/inkscape/tasks/silhouette.yml
@@ -1,7 +1,9 @@
 ---
-- name: install python-usb
+- name: install python-usb and usbip
   apt:
-    name: python-usb
+    name:
+      - python-usb
+      - usbip
     state: present
 
 - name: copy files
@@ -10,8 +12,29 @@
     dest: /usr/share/inkscape/extensions
     owner: root
     group: root
-    mode: "0644"
   loop:
     - sendto_silhouette.inx
     - sendto_silhouette.py
     - silhouette
+
+- name: usbip.sh should be executable
+  file:
+    dest: "/usr/share/inkscape/extensions/silhouette/usbip.sh"
+    owner: root
+    group: root
+    mode: "0755"
+
+- name: add lp group to guest account
+  lineinfile:
+    path: /etc/guest-account/groups
+    line: lp
+    create: yes
+
+- name: add sudoers config
+  copy:
+    content: "%lp ALL=(root) NOPASSWD:/usr/share/inkscape/extensions/silhouette/usbip.sh\n"
+    dest: /etc/sudoers.d/silhouette
+    owner: root
+    group: root
+    mode: "0644"
+
diff --git a/packer/ansible/roles/windowmanager/files/guest-account.sh b/packer/ansible/roles/windowmanager/files/guest-account.sh
index 968fa5c..bedde26 100644
--- a/packer/ansible/roles/windowmanager/files/guest-account.sh
+++ b/packer/ansible/roles/windowmanager/files/guest-account.sh
@@ -23,7 +23,7 @@ fi
 
 # read list of supplementary groups of the guest account from file
 if [ -f /etc/guest-account/groups ]; then
-  GROUPS="$(cat /etc/guest-account/groups)"
+  GROUPS="$(awk '{ if (NR==1) printf "%s", $0; else printf ",%s", $0; } END { print "" }' /etc/guest-account/groups)"
 fi
 
 is_system_user ()