diff --git a/boxes/build-debian-box.sh b/boxes/build-debian-box.sh
index 4b467bb..d1f7c25 100755
--- a/boxes/build-debian-box.sh
+++ b/boxes/build-debian-box.sh
@@ -98,10 +98,8 @@ chroot ${ROOTFS} apt-get install sudo -y --force-yes
 chroot ${ROOTFS} adduser vagrant sudo
 
 # Enable passwordless sudo for users under the "sudo" group
-cp ${ROOTFS}/etc/sudoers{,.orig}
-sed -i -e \
-      's/%sudo\s\+ALL=(ALL\(:ALL\)\?)\s\+ALL/%sudo ALL=NOPASSWD:ALL/g' \
-      ${ROOTFS}/etc/sudoers
+echo "vagrant ALL=NOPASSWD:ALL" > ${ROOTFS}/etc/sudoers.d/vagrant
+chmod 0440 ${ROOTFS}/etc/sudoers.d/vagrant
 
 
 ##################################################################################
diff --git a/boxes/build-ubuntu-box.sh b/boxes/build-ubuntu-box.sh
index 8ab5526..73001b9 100755
--- a/boxes/build-ubuntu-box.sh
+++ b/boxes/build-ubuntu-box.sh
@@ -81,10 +81,8 @@ echo $VAGRANT_KEY > ${ROOTFS}/home/vagrant/.ssh/authorized_keys
 chroot ${ROOTFS} chown -R vagrant: /home/vagrant/.ssh
 
 # Enable passwordless sudo for users under the "sudo" group
-cp ${ROOTFS}/etc/sudoers{,.orig}
-sed -i -e \
-      's/%sudo\s\+ALL=(ALL\(:ALL\)\?)\s\+ALL/%sudo ALL=NOPASSWD:ALL/g' \
-      ${ROOTFS}/etc/sudoers
+echo "vagrant ALL=NOPASSWD:ALL" > ${ROOTFS}/etc/sudoers.d/vagrant
+chmod 0440 ${ROOTFS}/etc/sudoers.d/vagrant
 
 
 ##################################################################################