diff --git a/tasks/main.yml b/tasks/main.yml
index 4803fea..9ce7cb6 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -53,6 +53,7 @@
     - ensure_ansible_prereq is defined
     - ensure_ansible_prereq.package_list is defined
     - ensure_ansible_prereq.package_list is iterable
+    - packages[item.name] is not defined
   ansible.builtin.package:
     name: '{{ item.name }}'
     state: '{{ item.state }}'