diff --git a/defaults/main.yml b/defaults/main.yml
index 1df3936a..41f2e157 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -173,7 +173,7 @@ lxc_cache_prep_post_commands: '## post command skipped ##'
 # or by providing the full path to a local file containing all of the variables
 # needed to prepare a container. built-in supported values are:
 #   [redhat-7.yml, suse-42.yml, ubuntu-16.04.yml, ubuntu-18.04.yml]
-lxc_user_defined_container: null
+#lxc_user_defined_container: null
 
 # Full path to the base image prep script. By default this will use the
 # named script for a given OS within the "templates/prep-scripts" directory.
diff --git a/tasks/main.yml b/tasks/main.yml
index a8329391..95179ac5 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -45,7 +45,7 @@
 - name: Gather container variables
   include_vars: "{{ item }}"
   with_first_found:
-    - "{{ lxc_user_defined_container }}"
+    - "{{ lxc_user_defined_container | default([]) }}"
     - "{{ ansible_distribution | lower }}-{{ ansible_distribution_version | lower }}.yml"
     - "{{ ansible_distribution | lower }}-{{ ansible_distribution_major_version | lower }}.yml"
     - "{{ ansible_os_family | lower }}-{{ ansible_distribution_major_version | lower }}.yml"