diff --git a/README.md b/README.md
index c2c4a70..45f241c 100644
--- a/README.md
+++ b/README.md
@@ -6,11 +6,19 @@ Installs Certbot (for Let's Encrypt) for RHEL/CentOS or Debian/Ubuntu.
 
 ## Requirements
 
-Let's Encrypt requires `git` to be installed. You can install using the `geerlingguy.git` role.
+Certbot requires Git to be installed. You can install Git using the `geerlingguy.git` role.
 
 ## Role Variables
 
-None.
+    certbot_repo: https://github.com/certbot/certbot.git
+    certbot_version: master
+    certbot_keep_updated: yes
+
+Certbot code repository options. This role clones the agent from the configured repo, then makes the `certbot-auto` script executable.
+
+    certbot_dir: /opt/certbot
+
+The directory inside which Certbot will be cloned.
 
 ## Dependencies
 
diff --git a/tasks/main.yml b/tasks/main.yml
index b04168d..5ff5548 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -5,3 +5,8 @@
     dest: "{{ certbot_dir }}"
     version: "{{ certbot_version }}"
     update: "{{ certbot_keep_updated }}"
+
+- name: Ensure certbot-auto is executable.
+  file:
+    path: "{{ certbot_dir }}/certbot-auto"
+    mode: 0755