diff --git a/tools/ubuntu-upgrade-infra-vm.sh b/tools/ubuntu-upgrade-infra-vm.sh
index 8316021b4..ceba43e2f 100755
--- a/tools/ubuntu-upgrade-infra-vm.sh
+++ b/tools/ubuntu-upgrade-infra-vm.sh
@@ -1,34 +1,35 @@
-#! /usr/bin/bash
+#!/usr/bin/env bash
 
 set -e
 
-if [[ ! $1 ]]; then
+if [[ -z "$1" ]]; then
     echo "Usage: infra-vm-ubuntu-upgrade.sh <infra-vm-hostname>"
     exit 2
 fi
 
-if [[ ! $KAYOBE_PATH ]]; then
+if [[ -z "$KAYOBE_PATH" ]]; then
     echo "Environment variable \$KAYOBE_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $KAYOBE_CONFIG_PATH ]]; then
+if [[ -z "$KAYOBE_CONFIG_PATH" ]]; then
     echo "Environment variable \$KAYOBE_CONFIG_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $ANSIBLE_ROLES_PATH ]]; then
+if [[ -z "$ANSIBLE_ROLES_PATH" ]]; then
     set -x
-    export ANSIBLE_ROLES_PATH=$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$KAYOBE_PATH/ansible/roles"
     set +x
 else
     set -x
-    export ANSIBLE_ROLES_PATH=$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles"
     set +x
 fi
 
 set -x
 
-kayobe playbook run $KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml -e os_release=noble --limit $1
+kayobe playbook run "$KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml" \
+    -e os_release=noble --limit "$1"
 
-kayobe infra vm host configure --limit $1 -e os_release=noble
+kayobe infra vm host configure --limit "$1" -e os_release=noble
diff --git a/tools/ubuntu-upgrade-overcloud.sh b/tools/ubuntu-upgrade-overcloud.sh
index 05d50068b..46dfd2e3a 100755
--- a/tools/ubuntu-upgrade-overcloud.sh
+++ b/tools/ubuntu-upgrade-overcloud.sh
@@ -1,36 +1,38 @@
-#! /usr/bin/bash
+#!/usr/bin/env bash
 
 set -e
 
-if [[ ! $1 ]]; then
+if [[ -z "$1" ]]; then
     echo "Usage: overcloud-ubuntu-upgrade.sh <overcloud-hostname>"
     exit 2
 fi
 
-if [[ ! $KAYOBE_PATH ]]; then
+if [[ -z "$KAYOBE_PATH" ]]; then
     echo "Environment variable \$KAYOBE_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $KAYOBE_CONFIG_PATH ]]; then
+if [[ -z "$KAYOBE_CONFIG_PATH" ]]; then
     echo "Environment variable \$KAYOBE_CONFIG_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $ANSIBLE_ROLES_PATH ]]; then
+if [[ -z "$ANSIBLE_ROLES_PATH" ]]; then
     set -x
-    export ANSIBLE_ROLES_PATH=$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$KAYOBE_PATH/ansible/roles"
     set +x
 else
     set -x
-    export ANSIBLE_ROLES_PATH=$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles"
     set +x
 fi
 
 set -x
 
-kayobe playbook run $KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml -e os_release=noble --limit $1
+kayobe playbook run "$KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml" \
+    -e os_release=noble --limit "$1"
 
-kayobe playbook run $KAYOBE_CONFIG_PATH/ansible/ovn-fix-chassis-priorities.yml
+kayobe playbook run "$KAYOBE_CONFIG_PATH/ansible/ovn-fix-chassis-priorities.yml"
+
+kayobe overcloud host configure --limit "$1" -e os_release=noble
 
-kayobe overcloud host configure --limit $1 -e os_release=noble
diff --git a/tools/ubuntu-upgrade-seed-hypervisor.sh b/tools/ubuntu-upgrade-seed-hypervisor.sh
index 259d0da5d..84350b8f7 100755
--- a/tools/ubuntu-upgrade-seed-hypervisor.sh
+++ b/tools/ubuntu-upgrade-seed-hypervisor.sh
@@ -1,29 +1,30 @@
-#! /usr/bin/bash
+#!/usr/bin/env bash
 
 set -e
 
-if [[ ! $KAYOBE_PATH ]]; then
+if [[ -z "$KAYOBE_PATH" ]]; then
     echo "Environment variable \$KAYOBE_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $KAYOBE_CONFIG_PATH ]]; then
+if [[ -z "$KAYOBE_CONFIG_PATH" ]]; then
     echo "Environment variable \$KAYOBE_CONFIG_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $ANSIBLE_ROLES_PATH ]]; then
+if [[ -z "$ANSIBLE_ROLES_PATH" ]]; then
     set -x
-    export ANSIBLE_ROLES_PATH=$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$KAYOBE_PATH/ansible/roles"
     set +x
 else
     set -x
-    export ANSIBLE_ROLES_PATH=$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles"
     set +x
 fi
 
 set -x
 
-kayobe playbook run $KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml -e os_release=noble --limit seed-hypervisor
+kayobe playbook run "$KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml" \
+    -e os_release=noble --limit seed-hypervisor
 
 kayobe seed hypervisor host configure -e os_release=noble
diff --git a/tools/ubuntu-upgrade-seed.sh b/tools/ubuntu-upgrade-seed.sh
index 96553225b..0c78cd250 100755
--- a/tools/ubuntu-upgrade-seed.sh
+++ b/tools/ubuntu-upgrade-seed.sh
@@ -1,29 +1,30 @@
-#! /usr/bin/bash
+#!/usr/bin/env bash
 
 set -e
 
-if [[ ! $KAYOBE_PATH ]]; then
+if [[ -z "$KAYOBE_PATH" ]]; then
     echo "Environment variable \$KAYOBE_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $KAYOBE_CONFIG_PATH ]]; then
+if [[ -z "$KAYOBE_CONFIG_PATH" ]]; then
     echo "Environment variable \$KAYOBE_CONFIG_PATH is not defined"
     exit 2
 fi
 
-if [[ ! $ANSIBLE_ROLES_PATH ]]; then
+if [[ -z "$ANSIBLE_ROLES_PATH" ]]; then
     set -x
-    export ANSIBLE_ROLES_PATH=$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$KAYOBE_PATH/ansible/roles"
     set +x
 else
     set -x
-    export ANSIBLE_ROLES_PATH=$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles
+    export ANSIBLE_ROLES_PATH="$ANSIBLE_ROLES_PATH:$KAYOBE_PATH/ansible/roles"
     set +x
 fi
 
 set -x
 
-kayobe playbook run $KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml -e os_release=noble --limit seed
+kayobe playbook run "$KAYOBE_CONFIG_PATH/ansible/ubuntu-upgrade.yml" \
+    -e os_release=noble --limit seed
 
 kayobe seed host configure -e os_release=noble