diff --git a/jenkins/VCA/start_build b/jenkins/VCA/start_build
index 59dce35..5830d0e 100755
--- a/jenkins/VCA/start_build
+++ b/jenkins/VCA/start_build
@@ -48,7 +48,7 @@
 systemctl enable lxd-bridge
 systemctl start lxd-bridge
 lxc image copy ubuntu:16.04 local: --alias ubuntu-xenial
-add-apt-repository ppa:juju/devel
+add-apt-repository -y ppa:juju/devel
 apt update
 apt install -y juju
 juju bootstrap juju localhost