diff --git a/roles/bootstrap/handlers/main.yml b/roles/bootstrap/handlers/main.yml
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..ed97d539c095cf1413af30cc23dea272095b97dd 100644
--- a/roles/bootstrap/handlers/main.yml
+++ b/roles/bootstrap/handlers/main.yml
@@ -0,0 +1 @@
+---
diff --git a/roles/bootstrap/tasks/main.yml b/roles/bootstrap/tasks/main.yml
index 2ed3c785aea45815d16c291830b37bf630677170..04848657029f2dce0f63974af0408c5559f385d2 100644
--- a/roles/bootstrap/tasks/main.yml
+++ b/roles/bootstrap/tasks/main.yml
@@ -1,25 +1,43 @@
 ---
 
 - name: Install sudo
-  apt: name=sudo state=installed
+  apt:
+    name: sudo
+    state: installed
 
 - name: Set-up the Ansible group
-  group: name=ansible system=yes
+  group:
+    name: ansible
+    system: yes
 
 - name: Set-up the Ansible user
-  user: name=ansible system=yes group=ansible shell=/bin/bash
+  user:
+    name: ansible
+    system: yes
+    group: ansible
+    shell: /bin/bash
 
 - name: Set-up authorized key for the Ansible user
-  authorized_key: user=ansible key="{{ ansible_key }}"
+  authorized_key:
+    user: ansible
+    key: "{{ ansible_key }}"
 
 - name: Set-up password-less sudo for the ansible user
-  copy: src=ansible_sudo dest=/etc/sudoers.d/ansible mode=0640 owner=root group=root
+  copy:
+    src: "ansible_sudo"
+    dest: "/etc/sudoers.d/ansible"
+    mode: 0640
+    owner: root
+    group: root
 
 - name: Revoke rights for Ansible user to log-in as root to server via ssh
-  authorized_key: user=root key="{{ ansible_key }}" state=absent
+  authorized_key:
+    user: root
+    key: "{{ ansible_key }}"
+    state: absent
 
 - name: Explicitly run all handlers
   include: ../handlers/main.yml
-  when: "handlers | default(False) | bool() == True"
+  when: "handlers | default(False) | bool() : :  True"
   tags:
     - handlers
diff --git a/roles/preseed/tasks/main.yml b/roles/preseed/tasks/main.yml
index d1c27126fdd64964f0c459802b25cd5bf0ab1601..27b4a84658d14d022f36b495bcacd22fde745922 100644
--- a/roles/preseed/tasks/main.yml
+++ b/roles/preseed/tasks/main.yml
@@ -1,13 +1,18 @@
 ---
 
 - name: Create directory for storing preseed configurations
-  file: path="{{ preseed_directory }}" mode=0750 state=directory
+  file:
+    path: "{{ preseed_directory }}"
+    mode: 0750
+    state: directory
 
 - name: Create preseed configuration file
-  template: src="preseed-jessie.cfg.j2" dest="{{ preseed_directory }}/{{ item }}.cfg"
-            mode=0640
-  with_items: "{{ groups['all'] }}"
+  template:
+    src: "preseed-jessie.cfg.j2"
+    dest: "{{ preseed_directory }}/{{ item }}.cfg"
+    mode: 0640
   when: item != "localhost"
+  with_items: "{{ groups['all'] }}"
 
 - name: Explicitly run all handlers
   include: ../handlers/main.yml
diff --git a/roles/xmpp_server/handlers/main.yml b/roles/xmpp_server/handlers/main.yml
index d2d22773b17a448237273335fb1e33e0a55eb09b..979e1c01ae4bc65689edacb90da2eee13524c9a7 100644
--- a/roles/xmpp_server/handlers/main.yml
+++ b/roles/xmpp_server/handlers/main.yml
@@ -1,4 +1,6 @@
 ---
 
 - name: Restart Prosody
-  service: name=prosody state=restarted
\ No newline at end of file
+  service:
+    name: prosody
+    state: restarted
diff --git a/roles/xmpp_server/tasks/main.yml b/roles/xmpp_server/tasks/main.yml
index 4642fdc36f209c9d9e0c38ff3ebf830f633d116d..4b6a9bd0ffe993c55f819ae84730e7aa7a0fd103 100644
--- a/roles/xmpp_server/tasks/main.yml
+++ b/roles/xmpp_server/tasks/main.yml
@@ -1,7 +1,8 @@
 ---
 
 - name: Install Python apt bindings
-  apt: name=python-apt
+  apt:
+    name: python-apt
 
 - name: Add Prosody repository apt key
   apt_key:
@@ -9,27 +10,38 @@
     state: present
 
 - name: Add Prosody repository
-  apt_repository: repo="deb http://packages.prosody.im/debian jessie main" state=present
+  apt_repository:
+    repo: "deb http://packages.prosody.im/debian jessie main"
+    state: present
 
 - name: Install Lua Sec library (needed for TLS)
-  apt: name=lua-sec state=installed
+  apt:
+    name: lua-sec
+    state: installed
 
 - name: Install Lua LDAP library
-  apt: name=lua-ldap state=installed
+  apt:
+    name: lua-ldap
+    state: installed
 
 - name: Install Prosody
-  apt: name=prosody state=installed
+  apt:
+    name: prosody
+    state: installed
 
 - name: Allow Prosody user to traverse the directory with TLS private keys
-  user: name=prosody append=yes groups=ssl-cert
+  user:
+    name: prosody
+    append: yes
+    groups: ssl-cert
 
 - name: Deploy XMPP TLS private key
   copy:
     dest: "/etc/ssl/private/{{ ansible_fqdn }}_xmpp.key"
     content: "{{ xmpp_tls_key }}"
-    mode: 0640
     owner: root
     group: prosody
+    mode: 0640
   notify:
     - Restart Prosody
 
@@ -37,30 +49,44 @@
   copy:
     dest: "/etc/ssl/certs/{{ ansible_fqdn }}_xmpp.pem"
     content: "{{ xmpp_tls_certificate }}"
-    mode: 0644
     owner: root
     group: root
+    mode: 0644
   notify:
     - Restart Prosody
 
 - name: Deploy configuration file for checking certificate validity via cron
-  copy: content="/etc/ssl/certs/{{ ansible_fqdn }}_xmpp.pem" dest="/etc/check_certificate/{{ ansible_fqdn }}_xmpp.conf"
-        owner=root group=root mode=0644
+  copy:
+    content: "/etc/ssl/certs/{{ ansible_fqdn }}_xmpp.pem"
+    dest: "/etc/check_certificate/{{ ansible_fqdn }}_xmpp.conf"
+    owner: root
+    group: root
+    mode: 0644
 
 - name: Set-up directory for storing additional Prosody modules
-  file: path=/usr/local/lib/prosody/modules/ state=directory mode=0755 owner=root group=root
+  file:
+    path: "/usr/local/lib/prosody/modules/"
+    state: directory
+    owner: root
+    group: root
+    mode: 0755
 
 - name: Deploy the Prosody mod_auth_ldap module
-  get_url: url=https://hg.prosody.im/prosody-modules/raw-file/tip/mod_auth_ldap/mod_auth_ldap.lua
-           dest=/usr/local/lib/prosody/modules/mod_auth_ldap.lua
+  get_url:
+    url: "https://hg.prosody.im/prosody-modules/raw-file/tip/mod_auth_ldap/mod_auth_ldap.lua"
+    dest: "/usr/local/lib/prosody/modules/mod_auth_ldap.lua"
 
 - name: Set-up file permissions for the Prosody mod_auth_ldap module
-  file: dest=/usr/local/lib/prosody/modules/mod_auth_ldap.lua owner=root group=root mode=0644
+  file:
+    dest: "/usr/local/lib/prosody/modules/mod_auth_ldap.lua"
+    owner: root
+    group: root
+    mode: 0644
 
 - name: Deploy Prosody configuration file
   template:
-    src: prosody.cfg.lua.j2
-    dest: /etc/prosody/prosody.cfg.lua
+    src: "prosody.cfg.lua.j2"
+    dest: "/etc/prosody/prosody.cfg.lua"
     owner: root
     group: prosody
     mode: 0640
@@ -68,15 +94,22 @@
     - Restart Prosody
 
 - name: Enable Prosody service on boot (workaround for systemctl broken handling of SysV)
-  command: rcconf -on prosody
+  command: "rcconf -on prosody"
   register: result
   changed_when: result.stderr == ""
 
 - name: Enable and start Prosody service
-  service: name=prosody state=started
+  service:
+    name: prosody
+    state: started
 
 - name: Deploy firewall configuration for XMPP server
-  copy: src="ferm_xmpp.conf" dest="/etc/ferm/conf.d/30-xmpp.conf" owner=root group=root mode=0640
+  copy:
+    src: "ferm_xmpp.conf"
+    dest: "/etc/ferm/conf.d/30-xmpp.conf"
+    owner: root
+    group: root
+    mode: 0640
   notify:
     - Restart ferm