diff --git a/roles/backup_client/molecule/default/prepare.yml b/roles/backup_client/molecule/default/prepare.yml
index 8bf085c6f7df3a7fdb8133d90fa225d7a19ceb9a..c779fe1fd9523abe1f8210e29f3dfdba4a66c0fa 100644
--- a/roles/backup_client/molecule/default/prepare.yml
+++ b/roles/backup_client/molecule/default/prepare.yml
@@ -36,10 +36,26 @@
       notify:
         - Restart ssh
 
+    - name: Drop the outdated public keys
+      file:
+        path: "{{ item }}"
+        state: absent
+      with_items:
+        - /etc/ssh/ssh_host_rsa_key.pub
+        - /etc/ssh/ssh_host_ed25519_key.pub
+        - /etc/ssh/ssh_host_ecdsa_key.pub
+
+    - name: Force the use of internal-sftp subsystem fro SFTP
+      lineinfile:
+        path: /etc/ssh/sshd_config
+        regexp: "^Subsystem.*sftp"
+        line: "Subsystem sftp internal-sftp"
+        state: present
+
     - name: Deploy custom SSH server configuration that chroots users
       copy:
-        src: "tests/data/backup_server_custom-sshd_config"
-        dest: "/etc/ssh/sshd_config"
+        src: "tests/data/backup_server-sshd-chroot_backup_users.conf"
+        dest: "/etc/ssh/sshd_config.d/chroot_backup_users.conf"
         owner: root
         group: root
         mode: 0600
@@ -86,7 +102,7 @@
       with_items:
         - /home/backupuser
         - /home/bak-param-mandatory-buster
-        - /home/bak-param-mandatory-buster
+        - /home/bak-param-mandatory-bullseye
 
     - name: Set-up duplicity backup directories
       file:
@@ -118,5 +134,7 @@
     backup_users:
       - name: bak-param-mandatory-buster
         key: "{{ lookup('file', 'tests/data/ssh/parameters-mandatory.pub') }}"
+      - name: bak-param-mandatory-bullseye
+        key: "{{ lookup('file', 'tests/data/ssh/parameters-mandatory.pub') }}"
       - name: backupuser
         key: "{{ lookup('file', 'tests/data/ssh/parameters-optional.pub') }}"