diff --git a/ct/checkmk.sh b/ct/checkmk.sh
index fa9d2c3b1..34d362a52 100644
--- a/ct/checkmk.sh
+++ b/ct/checkmk.sh
@@ -11,7 +11,7 @@ var_cpu="${var_cpu:-2}"
 var_ram="${var_ram:-2048}"
 var_disk="${var_disk:-6}"
 var_os="${var_os:-debian}"
-var_version="${var_version:-12}"
+var_version="${var_version:-13}"
 var_unprivileged="${var_unprivileged:-1}"
 
 header_info "$APP"
@@ -29,10 +29,11 @@ function update_script() {
   fi
 
   RELEASE=$(curl -fsSL https://api.github.com/repos/checkmk/checkmk/tags | grep "name" | awk '{print substr($2, 3, length($2)-4) }' | tr ' ' '\n' | grep -Ev 'rc|b' | sort -V | tail -n 1)
+  RELEASE="${RELEASE%%+*}"
   msg_info "Updating ${APP} to v${RELEASE}"
   $STD omd stop monitoring
   $STD omd cp monitoring monitoringbackup
-  curl -fsSL "https://download.checkmk.com/checkmk/${RELEASE}/check-mk-raw-${RELEASE}_0.bookworm_amd64.deb" -o "/opt/checkmk.deb"
+  curl -fsSL "https://download.checkmk.com/checkmk/${RELEASE}/check-mk-raw-${RELEASE}_0.$(get_os_info codename)_amd64.deb" -o "/opt/checkmk.deb"
   $STD apt-get install -y /opt/checkmk.deb
   $STD omd --force -V ${RELEASE}.cre update --conflict=install monitoring
   $STD omd start monitoring
diff --git a/install/checkmk-install.sh b/install/checkmk-install.sh
index fffb2a35e..154ded1a4 100644
--- a/install/checkmk-install.sh
+++ b/install/checkmk-install.sh
@@ -15,7 +15,8 @@ update_os
 
 msg_info "Install Checkmk"
 RELEASE=$(curl -fsSL https://api.github.com/repos/checkmk/checkmk/tags | grep "name" | awk '{print substr($2, 3, length($2)-4) }' | tr ' ' '\n' | grep -Ev 'rc|b' | sort -V | tail -n 1)
-curl -fsSL "https://download.checkmk.com/checkmk/${RELEASE}/check-mk-raw-${RELEASE}_0.bookworm_amd64.deb" -o "/opt/checkmk.deb"
+RELEASE="${RELEASE%%+*}"
+curl -fsSL "https://download.checkmk.com/checkmk/${RELEASE}/check-mk-raw-${RELEASE}_0.$(get_os_info codename)_amd64.deb" -o "/opt/checkmk.deb"
 $STD apt-get install -y /opt/checkmk.deb
 rm -rf /opt/checkmk.deb
 echo "${RELEASE}" >"/opt/checkmk_version.txt"