diff --git a/tc/obsw_tc_service5_17.py b/tc/obsw_tc_service5_17.py
index d1e5748e2e1c38282147c6f00778c399187108cf..69c7f30fdb18dc61210626f2065f6908a2eb28b8 100644
--- a/tc/obsw_tc_service5_17.py
+++ b/tc/obsw_tc_service5_17.py
@@ -12,6 +12,10 @@ from tc.obsw_pus_tc_packer import TcQueueT, PusTelecommand
 
 def pack_service5_test_into(tc_queue: TcQueueT) -> TcQueueT:
     tc_queue.appendleft(("print", "Testing Service 5"))
+    # invalid subservice
+    tc_queue.appendleft(("print", "Testing Service 5: Invalid subservice"))
+    command = PusTelecommand(service=5, subservice=1, ssc=500)
+    tc_queue.appendleft(command.pack_command_tuple())
     # disable events
     tc_queue.appendleft(("print", "Testing Service 5: Disable event"))
     command = PusTelecommand(service=5, subservice=6, ssc=500)