diff --git a/invokeai/app/services/session_processor/session_processor_default.py b/invokeai/app/services/session_processor/session_processor_default.py
index 7f9ce0b41a..5e8406c290 100644
--- a/invokeai/app/services/session_processor/session_processor_default.py
+++ b/invokeai/app/services/session_processor/session_processor_default.py
@@ -9,7 +9,6 @@ from invokeai.app.services.events.events_common import (
     BatchEnqueuedEvent,
     FastAPIEvent,
     QueueClearedEvent,
-    QueueEventBase,
     QueueItemStatusChangedEvent,
     SessionCanceledEvent,
     register_events,
@@ -294,10 +293,10 @@ class DefaultSessionProcessor(SessionProcessorBase):
         self._poll_now_event = ThreadEvent()
         self._cancel_event = ThreadEvent()
 
-        register_events(
-            events={SessionCanceledEvent, QueueClearedEvent, BatchEnqueuedEvent, QueueItemStatusChangedEvent},
-            func=self._on_queue_event,
-        )
+        register_events(events={SessionCanceledEvent}, func=self._on_session_canceled)
+        register_events(events={QueueClearedEvent}, func=self._on_queue_cleared)
+        register_events(events={BatchEnqueuedEvent}, func=self._on_batch_enqueued)
+        register_events(events={QueueItemStatusChangedEvent}, func=self._on_queue_item_status_changed)
 
         self._thread_semaphore = BoundedSemaphore(self._thread_limit)
 
@@ -332,25 +331,21 @@ class DefaultSessionProcessor(SessionProcessorBase):
     def _poll_now(self) -> None:
         self._poll_now_event.set()
 
-    async def _on_queue_event(self, event: FastAPIEvent[QueueEventBase]) -> None:
-        _event_name, payload = event
-        if (
-            isinstance(payload, SessionCanceledEvent)
-            and self._queue_item
-            and self._queue_item.item_id == payload.item_id
-        ):
+    async def _on_session_canceled(self, event: FastAPIEvent[SessionCanceledEvent]) -> None:
+        if self._queue_item and self._queue_item.item_id == event[1].item_id:
             self._cancel_event.set()
             self._poll_now()
-        elif (
-            isinstance(payload, QueueClearedEvent)
-            and self._queue_item
-            and self._queue_item.queue_id == payload.queue_id
-        ):
+
+    async def _on_queue_cleared(self, event: FastAPIEvent[QueueClearedEvent]) -> None:
+        if self._queue_item and self._queue_item.queue_id == event[1].queue_id:
             self._cancel_event.set()
             self._poll_now()
-        elif isinstance(payload, BatchEnqueuedEvent):
-            self._poll_now()
-        elif isinstance(payload, QueueItemStatusChangedEvent) and payload.status in ["completed", "failed", "canceled"]:
+
+    async def _on_batch_enqueued(self, event: FastAPIEvent[BatchEnqueuedEvent]) -> None:
+        self._poll_now()
+
+    async def _on_queue_item_status_changed(self, event: FastAPIEvent[QueueItemStatusChangedEvent]) -> None:
+        if self._queue_item and event[1].status in ["completed", "failed", "canceled"]:
             self._poll_now()
 
     def resume(self) -> SessionProcessorStatus: