diff --git a/roles/mail_forwarder/tasks/main.yml b/roles/mail_forwarder/tasks/main.yml
index ac4f96a3979379f3434207d6697635e209287ebb..247d66de50f442c34cb50c018feeeb7aa0c0569e 100644
--- a/roles/mail_forwarder/tasks/main.yml
+++ b/roles/mail_forwarder/tasks/main.yml
@@ -22,13 +22,13 @@
     dest: "/etc/ssl/certs/smtp_relay_truststore.pem"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
 
 - name: Generate the SMTP server Diffie-Hellman parameter
   openssl_dhparam:
     owner: root
     group: root
-    mode: 0640
+    mode: "0640"
     path: "/etc/ssl/private/{{ ansible_fqdn }}_smtp.dh.pem"
     size: 2048
   notify:
@@ -40,7 +40,7 @@
     dest: "/etc/mailname"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Postfix
 
@@ -50,7 +50,7 @@
     dest: "/etc/postfix/main.cf"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Postfix
 
@@ -108,7 +108,7 @@
     dest: "/etc/ferm/conf.d/20-mail.conf"
     owner: root
     group: root
-    mode: 0640
+    mode: "0640"
   notify:
     - Restart ferm