diff --git a/bec_widgets/utils/bec_dispatcher.py b/bec_widgets/utils/bec_dispatcher.py
index 9a93aa2a..4402ed98 100644
--- a/bec_widgets/utils/bec_dispatcher.py
+++ b/bec_widgets/utils/bec_dispatcher.py
@@ -162,9 +162,9 @@ class BECDispatcher:
             return
         self.client.connector.unregister(topics, cb=connected_slot)
         topics_str, _ = self.client.connector._convert_endpointinfo(topics)
-        self._slots[slot].difference_update(set(topics_str))
-        if not self._slots[slot]:
-            del self._slots[slot]
+        self._slots[connected_slot].difference_update(set(topics_str))
+        if not self._slots[connected_slot]:
+            del self._slots[connected_slot]
 
     def disconnect_topics(self, topics: Union[str, list]):
         self.client.connector.unregister(topics)
diff --git a/tests/unit_tests/test_bec_dispatcher.py b/tests/unit_tests/test_bec_dispatcher.py
index b24add04..bff12808 100644
--- a/tests/unit_tests/test_bec_dispatcher.py
+++ b/tests/unit_tests/test_bec_dispatcher.py
@@ -92,7 +92,9 @@ def test_dispatcher_2_cb_same_topic(bec_dispatcher_w_connector, qtbot, send_msg_
     bec_dispatcher.connect_slot(cb1, "topic1")
     bec_dispatcher.connect_slot(cb2, "topic1")
     assert len(bec_dispatcher.client.connector._topics_cb) == 1
+    assert len(bec_dispatcher._slots) == 2
     bec_dispatcher.disconnect_slot(cb1, "topic1")
+    assert len(bec_dispatcher._slots) == 1
 
     send_msg_event.set()
     qtbot.wait(10)