diff --git a/src/documents/tests/test_api_tasks.py b/src/documents/tests/test_api_tasks.py
index 4ff3f1c87..d12506e56 100644
--- a/src/documents/tests/test_api_tasks.py
+++ b/src/documents/tests/test_api_tasks.py
@@ -422,8 +422,8 @@ class TestGetTasksV9:
         assert len(response.data) == 1
         assert response.data[0]["task_name"] == "consume_file"
 
-    def test_filter_by_type_maps_to_trigger_source(self, v9_client: APIClient) -> None:
-        """?type=scheduled_task filter maps to trigger_source=scheduled for v9 compatibility."""
+    def test_filter_by_type_scheduled_task(self, v9_client: APIClient) -> None:
+        """?type=scheduled_task matches trigger_source=scheduled only."""
         PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.SCHEDULED)
         PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.WEB_UI)
 
@@ -433,6 +433,42 @@ class TestGetTasksV9:
         assert len(response.data) == 1
         assert response.data[0]["type"] == "scheduled_task"
 
+    def test_filter_by_type_auto_task_includes_all_auto_sources(
+        self,
+        v9_client: APIClient,
+    ) -> None:
+        """?type=auto_task matches system, email_consume, and folder_consume tasks."""
+        PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.SYSTEM)
+        PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.EMAIL_CONSUME)
+        PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.FOLDER_CONSUME)
+        PaperlessTaskFactory(
+            trigger_source=PaperlessTask.TriggerSource.MANUAL,
+        )  # excluded
+
+        response = v9_client.get(ENDPOINT, {"type": "auto_task"})
+
+        assert response.status_code == status.HTTP_200_OK
+        assert len(response.data) == 3
+        assert all(t["type"] == "auto_task" for t in response.data)
+
+    def test_filter_by_type_manual_task_includes_all_manual_sources(
+        self,
+        v9_client: APIClient,
+    ) -> None:
+        """?type=manual_task matches manual, web_ui, and api_upload tasks."""
+        PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.MANUAL)
+        PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.WEB_UI)
+        PaperlessTaskFactory(trigger_source=PaperlessTask.TriggerSource.API_UPLOAD)
+        PaperlessTaskFactory(
+            trigger_source=PaperlessTask.TriggerSource.SCHEDULED,
+        )  # excluded
+
+        response = v9_client.get(ENDPOINT, {"type": "manual_task"})
+
+        assert response.status_code == status.HTTP_200_OK
+        assert len(response.data) == 3
+        assert all(t["type"] == "manual_task" for t in response.data)
+
 
 @pytest.mark.django_db()
 class TestAcknowledge:
diff --git a/src/documents/views.py b/src/documents/views.py
index d56ced452..740eed792 100644
--- a/src/documents/views.py
+++ b/src/documents/views.py
@@ -3794,11 +3794,20 @@ class TasksViewSet(ReadOnlyModelViewSet[PaperlessTask]):
         "llmindex_update": PaperlessTask.TaskType.LLM_INDEX,
     }
 
-    # v9 backwards compat: maps old "type" query param values to new TriggerSource
-    _V9_TYPE_TO_TRIGGER_SOURCE = {
-        "auto_task": PaperlessTask.TriggerSource.SYSTEM,
-        "scheduled_task": PaperlessTask.TriggerSource.SCHEDULED,
-        "manual_task": PaperlessTask.TriggerSource.MANUAL,
+    # v9 backwards compat: maps old "type" query param values to new TriggerSource.
+    # Must match the reverse of TaskSerializerV9._TRIGGER_SOURCE_TO_V9_TYPE.
+    _V9_TYPE_TO_TRIGGER_SOURCES = {
+        "auto_task": [
+            PaperlessTask.TriggerSource.SYSTEM,
+            PaperlessTask.TriggerSource.EMAIL_CONSUME,
+            PaperlessTask.TriggerSource.FOLDER_CONSUME,
+        ],
+        "scheduled_task": [PaperlessTask.TriggerSource.SCHEDULED],
+        "manual_task": [
+            PaperlessTask.TriggerSource.MANUAL,
+            PaperlessTask.TriggerSource.WEB_UI,
+            PaperlessTask.TriggerSource.API_UPLOAD,
+        ],
     }
 
     _RUNNABLE_TASKS = {
@@ -3834,9 +3843,9 @@ class TasksViewSet(ReadOnlyModelViewSet[PaperlessTask]):
                 queryset = queryset.filter(task_type=mapped)
             task_type_old = self.request.query_params.get("type")
             if task_type_old is not None:
-                new_source = self._V9_TYPE_TO_TRIGGER_SOURCE.get(task_type_old)
-                if new_source:
-                    queryset = queryset.filter(trigger_source=new_source)
+                sources = self._V9_TYPE_TO_TRIGGER_SOURCES.get(task_type_old)
+                if sources:
+                    queryset = queryset.filter(trigger_source__in=sources)
         # v10+: direct task_id param for backwards compat
         task_id = self.request.query_params.get("task_id")
         if task_id is not None: