diff --git a/tc/obsw_tc_service5_17.py b/tc/obsw_tc_service5_17.py
index bd8f9a896c7fbc4a437f9a54c63e936b7438cd13..2f7290e208d9f3af7e5788204e087a948262d853 100644
--- a/tc/obsw_tc_service5_17.py
+++ b/tc/obsw_tc_service5_17.py
@@ -9,8 +9,13 @@
 
 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)