diff --git a/roles/wsgi_website/defaults/main.yml b/roles/wsgi_website/defaults/main.yml
index 1375ec02bbf08af687a1a1f969335448675a198e..e6d8898bd847f20f414bccf22e173e755fdfec82 100644
--- a/roles/wsgi_website/defaults/main.yml
+++ b/roles/wsgi_website/defaults/main.yml
@@ -1,11 +1,11 @@
 ---
 
 additional_nginx_config: {}
-enforce_https: True
+enforce_https: true
 packages: []
 rewrites: []
 static_locations: []
-use_paste: False
+use_paste: false
 virtualenv_packages: []
 environment_variables: {}
 https_tls_certificate: "{{ lookup('file', tls_certificate_dir + '/' + fqdn + '_https.pem') }}"
diff --git a/roles/wsgi_website/meta/main.yml b/roles/wsgi_website/meta/main.yml
index 7c80270ceb5a0b33bf6d593ac5c959efdddc6a28..2febb79042f268455339772450759aff51cef860 100644
--- a/roles/wsgi_website/meta/main.yml
+++ b/roles/wsgi_website/meta/main.yml
@@ -1,6 +1,6 @@
 ---
 
-allow_duplicates: yes
+allow_duplicates: true
 
 dependencies:
   - common
diff --git a/roles/wsgi_website/molecule/default/create.yml b/roles/wsgi_website/molecule/default/create.yml
index f8eb37cd4df02c540216c02791d0c50870986202..ce8657f9bae3be7f42731fd1efe77e87a62afcd9 100644
--- a/roles/wsgi_website/molecule/default/create.yml
+++ b/roles/wsgi_website/molecule/default/create.yml
@@ -2,7 +2,7 @@
 - name: Create
   hosts: localhost
   connection: local
-  gather_facts: False
+  gather_facts: false
   no_log: "{{ not lookup('env', 'MOLECULE_DEBUG') | bool }}"
   vars:
     molecule_file: "{{ lookup('env', 'MOLECULE_FILE') }}"
diff --git a/roles/wsgi_website/molecule/default/destroy.yml b/roles/wsgi_website/molecule/default/destroy.yml
index 3972a2df8fafe515b30a74f951499b83aae8449c..8f0a3703672765e77f4f1a3a8046a1f2b561a7a8 100644
--- a/roles/wsgi_website/molecule/default/destroy.yml
+++ b/roles/wsgi_website/molecule/default/destroy.yml
@@ -3,7 +3,7 @@
 - name: Destroy
   hosts: localhost
   connection: local
-  gather_facts: False
+  gather_facts: false
   no_log: "{{ not lookup('env', 'MOLECULE_DEBUG') | bool }}"
   vars:
     molecule_file: "{{ lookup('env', 'MOLECULE_FILE') }}"
diff --git a/roles/wsgi_website/molecule/default/molecule.yml b/roles/wsgi_website/molecule/default/molecule.yml
index 6921a1765a66ee3e3052cda605b7f9233b41c241..10af90780cb1b084286d6d1f0b00e7d29ce8546e 100644
--- a/roles/wsgi_website/molecule/default/molecule.yml
+++ b/roles/wsgi_website/molecule/default/molecule.yml
@@ -9,6 +9,8 @@ driver:
 
 lint:
   name: yamllint
+  options:
+    config-file: ../../.yamllint.yml
 
 platforms:
 
diff --git a/roles/wsgi_website/molecule/default/playbook.yml b/roles/wsgi_website/molecule/default/playbook.yml
index e98fa0928c876936a4e7ea7e8accc624378951ac..05ee8867ba63c15c189bcb14d3b212537eda4fa4 100644
--- a/roles/wsgi_website/molecule/default/playbook.yml
+++ b/roles/wsgi_website/molecule/default/playbook.yml
@@ -1,7 +1,7 @@
 ---
 
 - hosts: wsgi-website
-  become: yes
+  become: true
   vars:
     # common
     ca_certificates:
@@ -26,7 +26,7 @@
         - comment: Custom missing page.
           value: error_page 404 /my/own/error/page;
       admin_uid: 5000
-      enforce_https: no
+      enforce_https: false
       environment_indicator:
         background_colour: "#ff0000"
         text_colour: "#00ff00"
@@ -49,7 +49,7 @@
         - /static/
         - /media/
       uid: 5001
-      use_paste: no
+      use_paste: false
       virtualenv_packages:
         - dnspython==1.15.0,<1.20.0
         - ptpython==0.41
@@ -60,7 +60,7 @@
 
     - role: wsgi_website
       fqdn: parameters-paste-req
-      use_paste: yes
+      use_paste: true
       virtualenv_packages:
         - click==6.7
         - Flask==0.12.2
@@ -80,7 +80,7 @@
       https_tls_key: "{{ lookup('file', 'tests/data/x509/parameters-paste-req_https.key.pem') }}"
 
 - hosts: wsgi-website
-  become: yes
+  become: true
   tasks:
     # parameters-mandatory application
     - name: Set-up directories where application files are hosted at
diff --git a/roles/wsgi_website/molecule/default/prepare.yml b/roles/wsgi_website/molecule/default/prepare.yml
index 6792777f1ddb6f7ff8399383dd318c0a25ae41a5..bed5c4baf2b6830ae2dd982b8726cd0d30ed84c3 100644
--- a/roles/wsgi_website/molecule/default/prepare.yml
+++ b/roles/wsgi_website/molecule/default/prepare.yml
@@ -2,21 +2,21 @@
 
 - name: Prepare
   hosts: all
-  gather_facts: False
+  gather_facts: false
   tasks:
     - name: Install python for Ansible
       raw: test -e /usr/bin/python || (apt -y update && apt install -y python-minimal)
-      become: True
-      changed_when: False
+      become: true
+      changed_when: false
 
 - hosts: wsgi-website
-  become: yes
+  become: true
   tasks:
 
     - name: Update all caches to avoid errors due to missing remote archives
       apt:
-        update_cache: yes
-      changed_when: False
+        update_cache: true
+      changed_when: false
 
     - name: Set-up /etc/hosts entries
       lineinfile:
@@ -26,17 +26,17 @@
     - name: Install curl for testing redirects and webpage content
       apt:
         name: curl
-        state: installed
+        state: present
 
     - name: Install swaks for testing mail forwarding
       apt:
         name: swaks
-        state: installed
+        state: present
 
     - name: Install Postfix for testing mail forwarding (Exim4 not covered)
       apt:
         name: postfix
-        state: installed
+        state: present
 
     - name: Set-up group for an additional user
       group:
@@ -48,3 +48,6 @@
         name: user
         group: user
         shell: /bin/bash
+
+    - name: Rename the ss utility (see https://github.com/philpep/testinfra/pull/320)
+      command: "mv /bin/ss /bin/ss.bak"
diff --git a/roles/wsgi_website/molecule/default/tests/test_default.py b/roles/wsgi_website/molecule/default/tests/test_default.py
index e4c7de281e46a01bcde7f3db1b20809188c093b6..93b6a6a9714b3ed52a71626c9ac37cd553556a93 100644
--- a/roles/wsgi_website/molecule/default/tests/test_default.py
+++ b/roles/wsgi_website/molecule/default/tests/test_default.py
@@ -1,8 +1,10 @@
+import os
+
 import testinfra.utils.ansible_runner
 
 
 testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
-    '.molecule/ansible_inventory.yml').get_hosts('all')
+    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts(['all'])
 
 
 def test_hosts_file(host):
diff --git a/roles/wsgi_website/molecule/default/tests/test_parameters_mandatory.py b/roles/wsgi_website/molecule/default/tests/test_parameters_mandatory.py
index 96d572ddc7d2e8cdb843a54a86294e444c7cd9ec..7e6bf81a9ac362c017724967697b8434d76faa47 100644
--- a/roles/wsgi_website/molecule/default/tests/test_parameters_mandatory.py
+++ b/roles/wsgi_website/molecule/default/tests/test_parameters_mandatory.py
@@ -1,3 +1,4 @@
+import os
 import re
 import time
 
@@ -5,7 +6,7 @@ import testinfra.utils.ansible_runner
 
 
 testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
-    '.molecule/ansible_inventory.yml').get_hosts('all')
+    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts(['all'])
 
 
 def test_website_group(host):
diff --git a/roles/wsgi_website/molecule/default/tests/test_parameters_optional.py b/roles/wsgi_website/molecule/default/tests/test_parameters_optional.py
index 1a9e458d0e134c931a77915d39e4d948af1b14fd..01f7467495c4b006ecf2f4196a38e41c97264eca 100644
--- a/roles/wsgi_website/molecule/default/tests/test_parameters_optional.py
+++ b/roles/wsgi_website/molecule/default/tests/test_parameters_optional.py
@@ -1,3 +1,4 @@
+import os
 import re
 import time
 
@@ -5,7 +6,7 @@ import testinfra.utils.ansible_runner
 
 
 testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
-    '.molecule/ansible_inventory.yml').get_hosts('all')
+    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts(['all'])
 
 
 def test_website_group(host):
diff --git a/roles/wsgi_website/molecule/default/tests/test_parameters_paste_req.py b/roles/wsgi_website/molecule/default/tests/test_parameters_paste_req.py
index 7140c3f7c263b361d32705f814060ea8d2437171..4e8cc52684713101872aba659235e6c11db1baee 100644
--- a/roles/wsgi_website/molecule/default/tests/test_parameters_paste_req.py
+++ b/roles/wsgi_website/molecule/default/tests/test_parameters_paste_req.py
@@ -1,3 +1,4 @@
+import os
 import re
 import time
 
@@ -5,7 +6,7 @@ import testinfra.utils.ansible_runner
 
 
 testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
-    '.molecule/ansible_inventory.yml').get_hosts('all')
+    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts(['all'])
 
 
 def test_website_group(host):
diff --git a/roles/wsgi_website/tasks/main.yml b/roles/wsgi_website/tasks/main.yml
index 999471d12e0939611b5baca849f92f15afd8667b..7a07ae984c935b60ea89c7d034ac94ff1fffcb6b 100644
--- a/roles/wsgi_website/tasks/main.yml
+++ b/roles/wsgi_website/tasks/main.yml
@@ -12,7 +12,7 @@
     uid: "{{ admin_uid | default(omit) }}"
     group: "{{ user }}"
     shell: /bin/bash
-    createhome: yes
+    createhome: true
     home: "{{ home }}"
     state: present
 
@@ -46,8 +46,8 @@
     uid: "{{ uid | default(omit) }}"
     group: "{{ user }}"
     comment: "umask=0007"
-    system: yes
-    createhome: no
+    system: true
+    createhome: false
     state: present
     home: "{{ home }}"
 
@@ -55,7 +55,7 @@
   user:
     name: www-data
     groups: "{{ user }}"
-    append: yes
+    append: true
   notify:
     - Restart nginx
 
@@ -97,7 +97,7 @@
   command: '/usr/bin/virtualenv --prompt "({{ fqdn }})" "{{ home }}/virtualenv"'
   args:
     creates: "{{ home }}/virtualenv/bin/activate"
-  become: yes
+  become: true
   become_user: "{{ admin }}"
   tags:
     # [ANSIBLE0012] Commands should not change things if nothing needs doing
@@ -122,7 +122,7 @@
     mode: 0750
 
 - name: Install WSGI server
-  become: yes
+  become: true
   become_user: "{{ admin }}"
   pip:
     name: "{{ item.package }}"
@@ -143,7 +143,7 @@
   when: "wsgi_requirements"
 
 - name: Install additional packages in Python virtual environment
-  become: yes
+  become: true
   become_user: "{{ admin }}"
   pip:
     name: "{{ virtualenv_packages }}"
@@ -180,7 +180,7 @@
 - name: Enable the website service
   service:
     name: "{{ fqdn }}"
-    enabled: yes
+    enabled: true
     state: started
 
 - name: Create directory where static files can be served from
diff --git a/roles/wsgi_website/tasks/requirements.yml b/roles/wsgi_website/tasks/requirements.yml
index 9e7ddb29004fd92baa49f791fac5e4318f8f6589..b0f3017790cc32c625b9201631face87d355836c 100644
--- a/roles/wsgi_website/tasks/requirements.yml
+++ b/roles/wsgi_website/tasks/requirements.yml
@@ -20,7 +20,7 @@
     - wsgi_requirements.txt
 
 - name: Deploy Gunicorn requirements file for installation purposes
-  become: yes
+  become: true
   become_user: "{{ admin }}"
   template:
     src: "wsgi_requirements.txt.j2"
@@ -30,7 +30,7 @@
     mode: 0640
 
 - name: Install Gunicorn via requirements file
-  become: yes
+  become: true
   become_user: "{{ admin }}"
   pip:
     requirements: "{{ home }}/.wsgi_requirements.txt"