diff --git a/roles/bootstrap-os/tasks/flatcar.yml b/roles/bootstrap-os/tasks/flatcar.yml
index be74150a0..f330e0b62 100644
--- a/roles/bootstrap-os/tasks/flatcar.yml
+++ b/roles/bootstrap-os/tasks/flatcar.yml
@@ -23,7 +23,7 @@
 
 - name: Make interpreter discovery works on Flatcar
   set_fact:
-    ansible_interpreter_python_fallback: "{{ ansible_interpreter_python_fallback + [ '/opt/bin/python' ] }}"
+    ansible_interpreter_python_fallback: "{{ (ansible_interpreter_python_fallback | default([])) + [ '/opt/bin/python' ] }}"
 
 - name: Disable auto-upgrade
   systemd_service: