diff --git a/borgbackup.yml b/borgbackup.yml
index 8288244..5e98e23 100644
--- a/borgbackup.yml
+++ b/borgbackup.yml
@@ -1,12 +1,14 @@
+---
+
 - hosts: borgbackup
-  diff: yes
+  diff: true
   roles:
       - borgbackup
 - hosts: borg_client
-  diff: yes
+  diff: true
   roles:
       - borg-client
 - hosts: borg_server
-  diff: yes
+  diff: true
   roles:
       - borg-server
diff --git a/docker.yml b/docker.yml
index e25c572..befa528 100644
--- a/docker.yml
+++ b/docker.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: dockerservers
-  diff: yes
+  diff: true
   roles:
       - docker
diff --git a/ftp.yml b/ftp.yml
index ddff52f..5bb4011 100644
--- a/ftp.yml
+++ b/ftp.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: ftpservers
-  diff: yes
+  diff: true
   roles:
       - ftp
diff --git a/icecast2.yml b/icecast2.yml
index fade732..d2a6e69 100644
--- a/icecast2.yml
+++ b/icecast2.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: icecastservers
-  diff: yes
+  diff: true
   roles:
       - icecast2
diff --git a/loadbalancinghttp.yml b/loadbalancinghttp.yml
index 05c5404..0188f73 100644
--- a/loadbalancinghttp.yml
+++ b/loadbalancinghttp.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: loadbalancers
-  diff: yes
+  diff: true
   roles:
     - haproxy
diff --git a/mail.yml b/mail.yml
index 8baa00d..8159bd0 100644
--- a/mail.yml
+++ b/mail.yml
@@ -1,9 +1,11 @@
+---
+
 - hosts: mailservers
-  diff: yes
+  diff: true
   roles:
-      - postfix
-      - dovecot
-      - opendkim
-      - opendmarc
-      - spamassassin
-      - mailman
+    - postfix
+    - dovecot
+    - opendkim
+    - opendmarc
+    - spamassassin
+    - mailman
diff --git a/mariadb.yml b/mariadb.yml
index 17cc333..84db7f7 100644
--- a/mariadb.yml
+++ b/mariadb.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: mariadbservers
-  diff: yes
+  diff: true
   roles:
-      - mariadb
+    - mariadb
diff --git a/mumble.yml b/mumble.yml
index e432b3a..f9393a8 100644
--- a/mumble.yml
+++ b/mumble.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: mumbleservers
-  diff: yes
+  diff: true
   roles:
       - mumble
diff --git a/munin.yml b/munin.yml
index 34ef44b..9847c49 100644
--- a/munin.yml
+++ b/munin.yml
@@ -1,9 +1,11 @@
+---
+
 - hosts: all:!baybay-ponay.mateu.be:!muse-HP-EliteBook-820-G2.home.arpa
-  diff: yes
+  diff: true
   roles:
       - munin-client
 
 - hosts: muninservers
-  diff: yes
+  diff: true
   roles:
       - munin-server
diff --git a/nut.yml b/nut.yml
index 1db6253..77f5fa5 100644
--- a/nut.yml
+++ b/nut.yml
@@ -1,8 +1,10 @@
+---
+
 - hosts: nut_client
-  diff: yes
+  diff: true
   roles:
       - nut-client
 - hosts: nut_server
-  diff: yes
+  diff: true
   roles:
       - nut-server
diff --git a/pgsql.yml b/pgsql.yml
index ec61459..d98a30a 100644
--- a/pgsql.yml
+++ b/pgsql.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: pgsqlservers
-  diff: yes
+  diff: true
   roles:
       - postgres
diff --git a/php.yml b/php.yml
index c4388a0..b2072b0 100644
--- a/php.yml
+++ b/php.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: phpservers
-  diff: yes
+  diff: true
   roles:
     - php
diff --git a/site.yml b/site.yml
index 29ba104..964381a 100644
--- a/site.yml
+++ b/site.yml
@@ -1,3 +1,5 @@
+---
+
 - import_playbook: system.yml
 - import_playbook: usb.yml
 - import_playbook: smtprelay.yml
diff --git a/smtprelay.yml b/smtprelay.yml
index 1002b72..0b800f5 100644
--- a/smtprelay.yml
+++ b/smtprelay.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: all:!baybay-ponay.mateu.be:!machinbox.mateu.be:!mail.dmz.mateu.be:!muse-HP-EliteBook-820-G2.home.arpa
-  diff: yes
+  diff: true
   roles:
     - smtprelay
diff --git a/syslog.yml b/syslog.yml
index c268cc4..db0541b 100644
--- a/syslog.yml
+++ b/syslog.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: all:!baybay-ponay.mateu.be:!machinbox.mateu.be:!muse-HP-EliteBook-820-G2.home.arpa
-  diff: yes
+  diff: true
   roles:
       - rsyslog
diff --git a/unifi.yml b/unifi.yml
index 3856095..ed8c17a 100644
--- a/unifi.yml
+++ b/unifi.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: unifiservers
-  diff: yes
+  diff: true
   roles:
     - unifi
diff --git a/usb.yml b/usb.yml
index c32d5f4..b9de34a 100644
--- a/usb.yml
+++ b/usb.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: hypervisors
-  diff: yes
+  diff: true
   roles:
     - usb
diff --git a/webservers.yml b/webservers.yml
index 65faf48..199a482 100644
--- a/webservers.yml
+++ b/webservers.yml
@@ -1,5 +1,7 @@
+---
+
 - hosts: webservers
-  diff: yes
+  diff: true
   roles:
     - nginx
     - webapps
diff --git a/xmpp.yml b/xmpp.yml
index b82d800..d799687 100644
--- a/xmpp.yml
+++ b/xmpp.yml
@@ -1,4 +1,6 @@
+---
+
 - hosts: xmppservers
-  diff: yes
+  diff: true
   roles:
       - xmpp