diff --git a/roles/network/tasks/detected_network.yml b/roles/network/tasks/detected_network.yml
index 51a85ce86..976e46987 100644
--- a/roles/network/tasks/detected_network.yml
+++ b/roles/network/tasks/detected_network.yml
@@ -142,6 +142,10 @@
   register: second_gateway_found
   changed_when: False
 
+- assert:
+    that: second_gateway_found.stdout_lines | length == 1
+    fail_msg: "IIAB currently DOES NOT SUPPORT multiple secondary gateways."
+
 - name: Set exclude_devices if default gateway has been detected for {{ second_gateway_found.stdout }}
   set_fact:
     exclude_devices: "{{ second_gateway_found.stdout }}"