diff --git a/tasks/generate-certs.yml b/tasks/generate-certs.yml
index 59f1633..4716b14 100644
--- a/tasks/generate-certs.yml
+++ b/tasks/generate-certs.yml
@@ -3,7 +3,7 @@
 - name: Make sure we have an email
   assert:
     that:
-    - "certbot_register_email is not empty"
+    - "certbot_register_email == ''"
     msg: "You need to provide an email address you own to register with Let's Encrypt."
 
 - name: Register with Let's Encrypt