diff --git a/check_opnsense_traffic_for_host.py b/check_opnsense_traffic_for_host.py
index 51f2199..01c3969 100755
--- a/check_opnsense_traffic_for_host.py
+++ b/check_opnsense_traffic_for_host.py
@@ -88,6 +88,9 @@ def main():
             if response.status_code != 200:
                 print(f'UNKNOWN: unable to query OPNsense API for {interface}: {response.status_code}\n{response.text}')
                 sys.exit(nagios.UNKNOWN)
+            if isinstance(response.json(), list):
+                print(F'UNKNOWN - OPNsense returned wrong datatype:\n{response.json()}')
+
             for item in response.json().get(interface, {}).get('records', False):
                 if item['address'] == args.host:
                     traffic_data.append(item)