diff --git a/templates/prep-scripts/ubuntu_16_prep.sh.j2 b/templates/prep-scripts/ubuntu_16_prep.sh.j2
index 524965ff..732c0859 100644
--- a/templates/prep-scripts/ubuntu_16_prep.sh.j2
+++ b/templates/prep-scripts/ubuntu_16_prep.sh.j2
@@ -10,7 +10,7 @@ apt-get remove -y --purge snap* lxc* lxd* resolvconf* || true
 
 # Update base distribution
 apt-get update
-apt-get upgrade -y
+apt-get upgrade -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --force-yes
 apt-get install -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --force-yes {{ lxc_cache_distro_packages | join(' ') }}
 apt-get upgrade -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --force-yes
 rm -f /usr/bin/python
diff --git a/templates/prep-scripts/ubuntu_18_prep.sh.j2 b/templates/prep-scripts/ubuntu_18_prep.sh.j2
index 46c93a96..bf7e5a65 100644
--- a/templates/prep-scripts/ubuntu_18_prep.sh.j2
+++ b/templates/prep-scripts/ubuntu_18_prep.sh.j2
@@ -14,7 +14,7 @@ apt-get remove -y --purge snap* lxc* lxd* resolvconf* || true
 apt-get update
 apt-get install -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --force-yes gnupg
 
-apt-get upgrade -y
+apt-get upgrade -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --force-yes
 apt-get install -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --force-yes {{ lxc_cache_distro_packages | join(' ') }}
 apt-get upgrade -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --force-yes
 rm -f /usr/bin/python