diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6d5e786..95dd3bf 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -50,4 +50,3 @@ parallel_spec-Ruby 2.7.2-Puppet ~> 7:
     - bundle exec rake parallel_spec
   variables:
     PUPPET_GEM_VERSION: '~> 7'
-
diff --git a/.yamllint b/.yamllint
new file mode 100644
index 0000000..2e0edc0
--- /dev/null
+++ b/.yamllint
@@ -0,0 +1,11 @@
+---
+extends: default
+ignore: |
+  spec/
+  .rubocop.yml
+rules:
+  indentation:
+    spaces: 2
+  line-length:
+    level: warning
+    max: 140
diff --git a/appveyor.yml b/appveyor.yml
index a70c01e..e557bc4 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -33,7 +33,7 @@ install:
   - set PATH=C:\Ruby%RUBY_VERSION%\bin;%PATH%
   - bundle install --jobs 4 --retry 2 --without system_tests
   - type Gemfile.lock
-build: off
+build: 'off'
 test_script:
   - bundle exec puppet -V
   - ruby -v
diff --git a/data/common.yaml b/data/common.yaml
index ed97d53..2fbf0ff 100644
--- a/data/common.yaml
+++ b/data/common.yaml
@@ -1 +1 @@
----
+--- {}
diff --git a/hiera.yaml b/hiera.yaml
index 2251c23..74e5e00 100644
--- a/hiera.yaml
+++ b/hiera.yaml
@@ -9,9 +9,9 @@ hierarchy:
   - name: "osfamily/major release"
     paths:
       - "os/%{facts.os.family}/%{facts.os.release.major}.yaml"
-        # Used for Solaris
+      # Used for Solaris
       - "os/%{facts.os.family}/%{facts.kernelrelease}.yaml"
-        # Used to distinguish between Debian and Ubuntu
+      # Used to distinguish between Debian and Ubuntu
       - "os/%{facts.os.name}/%{facts.os.release.major}.yaml"
   - name: "osfamily"
     paths:
diff --git a/tests/vagrant/config.yaml b/tests/vagrant/config.yaml
index 665b392..7152702 100644
--- a/tests/vagrant/config.yaml
+++ b/tests/vagrant/config.yaml
@@ -1,3 +1,4 @@
+--- {}
 # -*- mode: yaml; -*-
 # Time-stamp: <Mon 2017-08-21 23:15 svarrette>
 ################################################################################
@@ -6,7 +7,7 @@
 # define additional VMs (agents) to deploy upon vagrant up (in addition to the
 # puppet master 'master')
 
-#___________________________________________
+# ___________________________________________
 # Complete / re-define the default boxes below
 # Format:
 #   :<os><version>: <username>/<box> # see https://vagrantcloud.com
@@ -17,7 +18,7 @@
 #   :debian8:     'debian/contrib-jessie64',
 #   :ubuntu14:    'ubuntu/trusty64'
 
-#_________________
+# _________________
 # Default settings
 # :defaults:
 #   :os: :centos7         # Default OS from the above box definition
@@ -25,7 +26,7 @@
 #   :vcpus: 1             # Default number of virtual CPUs
 #   :vbguest_auto_update: 1  # check/update box guest additions
 
-#____________________
+# ____________________
 # Network settings
 # :network:
 #   :domain: 'vagrant.dev'      # network domain to use
@@ -33,7 +34,7 @@
 #   :ip_offset: 10
 #   # client / VMs defined below will start on xx.xx.xx.<ip_offset>
 
-#___________________________________________________________
+# ___________________________________________________________
 # VMs / Vagrant boxes to define apart from the puppet master
 # Format:
 # <name>: