diff --git a/README.md b/README.md
index 95f8239..fe86a53 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ Generally, installing from source (see section `Source Installation from Git`) l
 The variable `certbot_install_from_source` controls whether to install Certbot from Git or package management. The latter is the default, so the variable defaults to `no`.
 
     certbot_auto_renew: true
-    certbot_auto_renew_user: "{{ ansible_user }}"
+    certbot_auto_renew_user: "{{ ansible_user | default(lookup('env', 'USER')) }}"
     certbot_auto_renew_hour: 3
     certbot_auto_renew_minute: 30
     certbot_auto_renew_options: "--quiet --no-self-upgrade"
diff --git a/molecule/default/playbook-source-install.yml b/molecule/default/playbook-source-install.yml
index 268ae13..77ced51 100644
--- a/molecule/default/playbook-source-install.yml
+++ b/molecule/default/playbook-source-install.yml
@@ -5,6 +5,7 @@
 
   vars:
     certbot_install_from_source: true
+    certbot_auto_renew_user: root
 
   pre_tasks:
     - name: Update apt cache.
diff --git a/molecule/default/playbook.yml b/molecule/default/playbook.yml
index 6552819..9d6e5e7 100644
--- a/molecule/default/playbook.yml
+++ b/molecule/default/playbook.yml
@@ -3,6 +3,9 @@
   hosts: all
   become: true
 
+  vars:
+    certbot_auto_renew_user: root
+
   pre_tasks:
     - name: Update apt cache.
       apt: update_cache=yes cache_valid_time=600