diff --git a/debian/changelog b/debian/changelog
index 33233a26..41b3beda 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -2,6 +2,10 @@ livecd-rootfs (2.541) UNRELEASED; urgency=medium
 
   * Remove device nodes from Docker images. (LP: #1645468) 
 
+  [ Robert C Jennings ]
+  * Add the server snap seed to the ubuntu-cpc project
+  * Allow hooks to replace generic snap assertion
+
  -- Michael Hudson-Doyle <mwhudson@debian.org>  Wed, 26 Sep 2018 12:43:23 +1200
 
 livecd-rootfs (2.540) cosmic; urgency=medium
diff --git a/live-build/auto/config b/live-build/auto/config
index fd2ce64d..5ab67fac 100755
--- a/live-build/auto/config
+++ b/live-build/auto/config
@@ -696,6 +696,9 @@ case $PROJECT:${SUBPROJECT:-} in
 	ubuntu:*|kubuntu*:*|lubuntu*:*|xubuntu*:*|ubuntu-mate*:*|ubuntustudio*:*|ubuntukylin*:*|ubuntu-budgie*:*)
 		BASE_SEED='desktop'
 		;;
+	ubuntu-cpc:*)
+		BASE_SEED='server'
+		;;
 	ubuntu-server:live)
 		BASE_SEED='server'
 		# subiquity is seeded but in a separate squashfs via hooks; set HOOK_SNAPS and ALL_SNAPS.
diff --git a/live-build/functions b/live-build/functions
index 4441f2b1..cf68ba16 100644
--- a/live-build/functions
+++ b/live-build/functions
@@ -427,6 +427,16 @@ snap_prepare_assertions() {
     local brand="$(echo $CUSTOM_BRAND_MODEL | cut -d: -f 1)"
     local model="$(echo $CUSTOM_BRAND_MODEL | cut -d: -f 2)"
 
+    # Clear the assertions if they already exist
+    if [ -e "$model_assertion" ] ; then
+        existing_model=$(awk '/^model: / {print $2}' $model_assertion)
+        existing_brand=$(awk '/^brand-id: / {print $2}' $model_assertion)
+        echo "snap_prepare_assertions: replacing $existing_brand:$existing_model with $brand:$model"
+        rm "$model_assertion"
+        rm "$account_key_assertion"
+        rm "$account_assertion"
+    fi
+
     if ! [ -e "$model_assertion" ] ; then
         snap known --remote model series=16 \
             model=$model brand-id=$brand \
@@ -441,7 +451,6 @@ snap_prepare_assertions() {
             > "$account_key_assertion"
     fi
 
-
     if ! [ -e "$account_assertion" ] ; then
         local account=$(sed -n -e's/account-id: //p' < "$account_key_assertion")
         snap known --remote account account-id=$account \
@@ -468,13 +477,16 @@ snap_prepare() {
 }
 
 snap_preseed() {
-    # Preseed a snap in the image
+    # Preseed a snap in the image (snap_prepare must be called once prior)
     local CHROOT_ROOT=$1
     local SNAP=$2
     # Per Ubuntu policy, all seeded snaps (with the exception of the core
     # snap) must pull from stable/ubuntu-$(release_ver) as their channel.
     local CHANNEL=${3:-"stable/ubuntu-$(release_ver)"}
 
-    snap_prepare $CHROOT_ROOT
+    if [ ! -e "$CHROOT_ROOT/var/lib/snapd/seed/assertions/model" ]; then
+        echo "ERROR: Snap model assertion not present, snap_prepare must be called"
+        exit 1
+    fi
     _snap_preseed $CHROOT_ROOT $SNAP $CHANNEL
 }