diff --git a/src/ahriman/web/views/v1/auditlog/event_bus.py b/src/ahriman/web/views/v1/auditlog/event_bus.py
index c3a019a4..61d75452 100644
--- a/src/ahriman/web/views/v1/auditlog/event_bus.py
+++ b/src/ahriman/web/views/v1/auditlog/event_bus.py
@@ -19,7 +19,7 @@
 #
 import json
 
-from aiohttp.web import StreamResponse
+from aiohttp.web import HTTPBadRequest, StreamResponse
 from aiohttp_sse import EventSourceResponse, sse_response
 from asyncio import Queue, QueueShutDown, wait_for
 from typing import ClassVar
@@ -69,6 +69,7 @@ class EventBusView(BaseView):
         summary="Live updates",
         description="Stream live updates via SSE",
         permission=GET_PERMISSION,
+        error_400_enabled=True,
         error_404_description="Repository is unknown",
         schema=SSESchema(many=True),
         query_schema=EventBusFilterSchema,
@@ -79,8 +80,14 @@ class EventBusView(BaseView):
 
         Returns:
             StreamResponse: 200 with streaming updates
+
+        Raises:
+            HTTPBadRequest: if invalid event type is supplied
         """
-        topics = [EventType(event) for event in self.request.query.getall("event", [])] or None
+        try:
+            topics = [EventType(event) for event in self.request.query.getall("event", [])] or None
+        except ValueError as ex:
+            raise HTTPBadRequest(reason=str(ex))
         event_bus = self.service().event_bus
 
         async with sse_response(self.request) as response:
diff --git a/tests/ahriman/web/views/v1/auditlog/test_view_v1_auditlog_event_bus.py b/tests/ahriman/web/views/v1/auditlog/test_view_v1_auditlog_event_bus.py
index 5e7bad0c..1621b314 100644
--- a/tests/ahriman/web/views/v1/auditlog/test_view_v1_auditlog_event_bus.py
+++ b/tests/ahriman/web/views/v1/auditlog/test_view_v1_auditlog_event_bus.py
@@ -33,8 +33,9 @@ async def test_get_permission() -> None:
     """
     must return correct permission for the request
     """
-    request = pytest.helpers.request("", "", "GET")
-    assert await EventBusView.get_permission(request) == UserAccess.Full
+    for method in ("GET",):
+        request = pytest.helpers.request("", "", method)
+        assert await EventBusView.get_permission(request) == UserAccess.Full
 
 
 def test_routes() -> None:
@@ -98,6 +99,17 @@ async def test_get_with_topic_filter(client: TestClient, package_ahriman: Packag
     assert EventType.PackageRemoved not in body
 
 
+async def test_get_bad_request(client: TestClient) -> None:
+    """
+    must return bad request for invalid event type
+    """
+    response_schema = pytest.helpers.schema_response(EventBusView.get, code=400)
+
+    response = await client.get("/api/v1/events/stream", params={"event": "invalid"})
+    assert response.status == 400
+    assert not response_schema.validate(await response.json())
+
+
 async def test_get_not_found(client: TestClient) -> None:
     """
     must return not found for unknown repository
@@ -114,6 +126,5 @@ async def test_get_connection_reset(client: TestClient, mocker: MockerFixture) -
     must handle connection reset
     """
     mocker.patch.object(EventBusView, "_run", side_effect=ConnectionResetError)
-
     response = await client.get("/api/v1/events/stream")
     assert response.status == 200