diff --git a/defaults/main.yml b/defaults/main.yml
index 7a71d80..fefbe1d 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -29,8 +29,7 @@ certbot_register_email: ''
 certbot_register_command: "{{ certbot_script }} register --non-interactive --agree-tos --email {{ certbot_register_email }}"
 
 # The domains to generate certs for
-certbot_domains:
-- 'example.com'
+certbot_domains: []
 
 # The command to run to generate the certificates
 certbot_cert_command: "{{ certbot_script }} certonly --noninteractive --standalone"
diff --git a/tasks/generate-certs.yml b/tasks/generate-certs.yml
index ee6c913..5f3e797 100644
--- a/tasks/generate-certs.yml
+++ b/tasks/generate-certs.yml
@@ -6,6 +6,12 @@
     - "certbot_register_email != ''"
     msg: "You need to provide an email address you own to register with Let's Encrypt."
 
+- name: Make sure we have domains
+  assert:
+    that:
+    - "certbot_domains != []"
+    msg: "You need to provide at least one domain to generate certificates for."
+
 - name: Register with Let's Encrypt
   command: "{{ certbot_register_command }}"
   args: