diff --git a/test/unit/test_watcher.py b/test/unit/test_watcher.py
index 2c1e11f..ce693fb 100644
--- a/test/unit/test_watcher.py
+++ b/test/unit/test_watcher.py
@@ -81,6 +81,15 @@ def test_init(watcher):
     assert type(watcher.responder) is Responder
 
 
+def test_init_no_key(db_manager):
+    try:
+        Watcher(db_manager, pisa_sk_file=None)
+        assert False
+
+    except ValueError:
+        assert True
+
+
 def test_add_appointment(run_bitcoind, watcher):
     # The watcher automatically fires do_watch and do_subscribe on adding an appointment if it is asleep (initial state)
     # Avoid this by setting the state to awake.
@@ -96,6 +105,12 @@ def test_add_appointment(run_bitcoind, watcher):
         assert added_appointment is True
         assert is_signature_valid(appointment, sig, public_key)
 
+        # Check that we can also add an already added appointment (same locator)
+        added_appointment, sig = watcher.add_appointment(appointment)
+
+        assert added_appointment is True
+        assert is_signature_valid(appointment, sig, public_key)
+
 
 def test_sign_appointment(watcher):
     appointment, _ = generate_dummy_appointment(start_time_offset=START_TIME_OFFSET, end_time_offset=END_TIME_OFFSET)