diff --git a/roles/xmpp_server/tasks/main.yml b/roles/xmpp_server/tasks/main.yml
index b80153e1d539b591c2eb9a67897921216f552c5c..6f344d9686dd1c5a062a5e845cd6eb85d11796ab 100644
--- a/roles/xmpp_server/tasks/main.yml
+++ b/roles/xmpp_server/tasks/main.yml
@@ -9,7 +9,7 @@
     dest: /etc/apt/sources.list.d/backports.list
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   register: backports_repository_configuration
 
 - name: Update apt cache if backports repository configuration changed (for immediate use)  # noqa no-handler
@@ -50,7 +50,7 @@
     content: "{{ xmpp_tls_key }}"
     owner: root
     group: prosody
-    mode: 0640
+    mode: "0640"
   notify:
     - Restart Prosody
 
@@ -60,7 +60,7 @@
     content: "{{ xmpp_tls_certificate }}"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Prosody
 
@@ -68,7 +68,7 @@
   openssl_dhparam:
     owner: root
     group: prosody
-    mode: 0640
+    mode: "0640"
     path: "/etc/ssl/private/{{ ansible_fqdn }}_xmpp.dh.pem"
     size: 2048
   notify:
@@ -80,7 +80,7 @@
     dest: "/etc/check_certificate/{{ ansible_fqdn }}_xmpp.conf"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
 
 - name: Deploy script for validating Prosody certificate
   copy:
@@ -88,7 +88,7 @@
     dest: "/usr/local/bin/check_prosody_certificate.sh"
     owner: root
     group: root
-    mode: 0755
+    mode: "0755"
 
 - name: Set-up crontab task that runs the Prosody certificate checker script once a day
   copy:
@@ -96,7 +96,7 @@
     dest: "/etc/cron.d/check_prosody_certificate"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
 
 - name: Deploy LDAP client configuration (for validating LDAP server certificate)
   copy:
@@ -104,7 +104,7 @@
     dest: "/var/lib/prosody/.ldaprc"
     owner: root
     group: prosody
-    mode: 0640
+    mode: "0640"
   notify:
     - Restart Prosody
 
@@ -114,7 +114,7 @@
     dest: "/etc/prosody/prosody.cfg.lua"
     owner: root
     group: prosody
-    mode: 0640
+    mode: "0640"
   notify:
     - Restart Prosody
 
@@ -130,7 +130,7 @@
     dest: "/etc/ferm/conf.d/30-xmpp.conf"
     owner: root
     group: root
-    mode: 0640
+    mode: "0640"
   notify:
     - Restart ferm