diff --git a/class/HW4F_DESKTOP.var b/class/HW4F_DESKTOP.var
index d5b0364..3c3c572 100644
--- a/class/HW4F_DESKTOP.var
+++ b/class/HW4F_DESKTOP.var
@@ -13,3 +13,5 @@ username=user
 USERPW='$5$n4TiokMaqws2PC/i$eqDh77it8N/haBU6OeE6WqbBjI0E1IUczp2EJ7Tr4J/'
 
 SUPRESS_GNOME_INITIAL_SCREEN=1
+
+APTPROXY=http://hw4f-fai:3142
diff --git a/hooks/updatebase.UBUNTU b/hooks/updatebase.UBUNTU
index 2d1161c..a9ca6a4 100755
--- a/hooks/updatebase.UBUNTU
+++ b/hooks/updatebase.UBUNTU
@@ -9,6 +9,11 @@ deb $ubuntumirror/ubuntu $ubuntudist-updates main restricted universe multiverse
 deb $ubuntumirror/ubuntu $ubuntudist-security main restricted universe multiverse
 EOM
 
+if [ -n "$APTPROXY" ]; then
+    echo "Acquire::http::Proxy \"$APTPROXY\";" > $target/etc/apt/apt.conf.d/02proxy
+else
+    rm -f $target/etc/apt/apt.conf.d/02proxy
+fi
 
 # https://lists.uni-koeln.de/pipermail/linux-fai/2016-July/011398.html
 # In Ubuntu 16.04 (but not 14.04), the locales configuration mechanism has
diff --git a/package_config/HW4F_DESKTOP b/package_config/HW4F_DESKTOP
index 2b2f080..2ae9b04 100644
--- a/package_config/HW4F_DESKTOP
+++ b/package_config/HW4F_DESKTOP
@@ -12,5 +12,3 @@ libreoffice-help-de
 ubuntu-software
 ubuntu-snappy
 snapd
-
-APTPROXY=http://hw4f-fai:3142
diff --git a/scripts/HW4F_DESKTOP_LAST/00-remove-proxy b/scripts/HW4F_DESKTOP_LAST/00-remove-proxy
index af8401a..28564db 100755
--- a/scripts/HW4F_DESKTOP_LAST/00-remove-proxy
+++ b/scripts/HW4F_DESKTOP_LAST/00-remove-proxy
@@ -31,5 +31,5 @@ if contains "$DISTS_TO_UPGRADE" "$release"; then
 fi
 
 if [ ! "$KEEP_PROXY_FOR_UPGRADE" ]; then
-	$ROOTCMD rm -f /etc/apt/apt.conf.d/00-proxy
+	rm -f $target/etc/apt/apt.conf.d/02proxy
 fi