diff --git a/src/zmb-member/install-service.sh b/src/zmb-member/install-service.sh
index c2fdfcf..2dd69c3 100644
--- a/src/zmb-member/install-service.sh
+++ b/src/zmb-member/install-service.sh
@@ -12,10 +12,11 @@ source /root/constants-service.conf
 # add wsdd package repo
 apt-key adv --fetch-keys https://pkg.ltec.ch/public/conf/ltec-ag.gpg.key
 echo "deb https://pkg.ltec.ch/public/ $(lsb_release -cs) main" > /etc/apt/sources.list.d/wsdd.list
+echo "deb http://ftp.de.debian.org/debian $(lsb_release -cs)-backports main contrib" > /etc/apt/sources.list.d/$(lsb_release -cs)-backports.list
 
 apt update
 
-DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt install -y -o DPkg::options::="--force-confdef" -o DPkg::options::="--force-confold" acl samba winbind libpam-winbind libnss-winbind krb5-user krb5-config samba-dsdb-modules samba-vfs-modules wsdd
+DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt install -y -o DPkg::options::="--force-confdef" -o DPkg::options::="--force-confold" -t $(lsb_release -cs)-backports acl samba winbind libpam-winbind libnss-winbind krb5-user krb5-config samba-dsdb-modules samba-vfs-modules wsdd
 
 mv /etc/krb5.conf /etc/krb5.conf.bak
 cat > /etc/krb5.conf <<EOF