diff --git a/roles/prereq/defaults/main.yml b/roles/prereq/defaults/main.yml
index b5a8c06..5791bc4 100644
--- a/roles/prereq/defaults/main.yml
+++ b/roles/prereq/defaults/main.yml
@@ -1,4 +1,4 @@
-
+---
 # Copyright 2017-present Open Networking Foundation
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -13,19 +13,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
 #
 # variables needed to be defined in user's playbook
 #
-#
 # user-configurable defaults
 #
 # default install path
+
 docker_tools_path: '/usr/local/bin'
 docker_tools_pipework_exe_url: https://raw.githubusercontent.com/jpetazzo/pipework/master/pipework
 openvswitch_url: http://openvswitch.org/releases
 openvswitch_version: '2.5.0'
-#docker variables
+
+# docker variables
 docker:
     registry: "{{ docker_registry | default('docker-registry:5000') }}"
     image_version: "{{ docker_image_version | default('latest') }}"
diff --git a/roles/prereq/tasks/main.yml b/roles/prereq/tasks/main.yml
index 32ce311..baf0e8e 100644
--- a/roles/prereq/tasks/main.yml
+++ b/roles/prereq/tasks/main.yml
@@ -1,4 +1,4 @@
-
+---
 # Copyright 2017-present Open Networking Foundation
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -13,11 +13,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
----
 - name: Install Cord tester prerequisites
-  become: yes
-  apt: name={{ item }} state=latest force=yes
+  become: true
+  apt: name={{ item }} state=latest force=true
   with_items:
     - wget
     - python
@@ -31,7 +29,7 @@
     - libffi-dev
 
 - name: Install Python Prerequisites for cord tester
-  become: yes
+  become: true
   pip: name={{ item }} state=latest
   with_items:
     - nose
@@ -59,20 +57,20 @@
   pip: name=paramiko version=1.10.1 state=present
 
 - name: Download Openvswitch {{ openvswitch_version }}
-  become:  yes
+  become: true
   get_url:
     url: "{{ openvswitch_url }}/openvswitch-{{ openvswitch_version }}.tar.gz"
     dest: "/home/{{ ansible_user }}/openvswitch-{{ openvswitch_version }}.tar.gz"
-    force: yes
+    force: true
 
-- name:  Untar Openvswitch {{ openvswitch_version }}
-  become: yes
+- name: Untar Openvswitch {{ openvswitch_version }}
+  become: true
   unarchive:
     src=openvswitch-{{ openvswitch_version }}.tar.gz
     dest=/home/{{ ansible_user }}
 
 - name: Build Openvswitch {{ openvswitch_version }}
-  become: yes
+  become: true
   shell: "{{ item }}"
   args:
     chdir: "/home/{{ ansible_user }}/openvswitch-{{ openvswitch_version }}"
@@ -90,15 +88,15 @@
     - "openvswitch-{{ openvswitch_version }}"
 
 - name: install Pipework
-  sudo: True
+  sudo: true
   get_url:
     url: "{{ docker_tools_pipework_exe_url }}"
     dest: "{{ docker_tools_path }}/pipework"
-    force: yes
+    force: true
     mode: "a+x"
 
 - name: Pull cord test container
-  become: yes
+  become: true
   docker:
     name: cord-test
     image: "{{ docker.registry }}/cordtest/nose:{{ docker.image_version }}"
@@ -106,7 +104,7 @@
     state: absent
 
 - name: Pull test radius container
-  become: yes
+  become: true
   docker:
     name: cord-radius
     image: "{{ docker.registry }}/cordtest/radius:{{ docker.image_version }}"
@@ -114,7 +112,7 @@
     state: absent
 
 - name: Pull test quagga container
-  become: yes
+  become: true
   docker:
     name: cord-quagga
     image: "{{ docker.registry }}/cordtest/quagga:{{ docker.image_version }}"
@@ -122,7 +120,7 @@
     state: absent
 
 - name: Pull onosproject
-  become: yes
+  become: true
   docker:
     name: cord-test-onos
     image: "{{ docker.registry }}/onosproject/onos:{{ docker.image_version }}"