diff --git a/ai_diffusion/custom_workflow.py b/ai_diffusion/custom_workflow.py
index 40eb76849..100b41230 100644
--- a/ai_diffusion/custom_workflow.py
+++ b/ai_diffusion/custom_workflow.py
@@ -4,7 +4,7 @@
 from enum import Enum
 from copy import copy
 from dataclasses import dataclass
-from typing import Any, Awaitable, Callable, NamedTuple, Literal
+from typing import Any, Awaitable, Callable, NamedTuple, Literal, TYPE_CHECKING
 from pathlib import Path
 from PyQt5.QtCore import Qt, QObject, QUuid, QAbstractListModel, QSortFilterProxyModel, QModelIndex
 from PyQt5.QtCore import pyqtSignal
@@ -13,7 +13,6 @@
 from .comfy_workflow import ComfyWorkflow
 from .connection import Connection
 from .image import Bounds, Image
-from .layer import LayerManager
 from .jobs import Job, JobParams, JobQueue, JobKind
 from .properties import Property, ObservableProperties
 from .style import Styles
@@ -21,6 +20,9 @@
 from .ui import theme
 from . import eventloop
 
+if TYPE_CHECKING:
+    from .layer import LayerManager
+
 
 class WorkflowSource(Enum):
     document = 0
@@ -390,7 +392,7 @@ def graph(self):
     def metadata(self):
         return self._metadata
 
-    def collect_parameters(self, layers: LayerManager, bounds: Bounds):
+    def collect_parameters(self, layers: "LayerManager", bounds: Bounds):
         params = copy(self.params)
         for md in self.metadata:
             param = params.get(md.name)
diff --git a/ai_diffusion/jobs.py b/ai_diffusion/jobs.py
index 962145be1..412d2d30d 100644
--- a/ai_diffusion/jobs.py
+++ b/ai_diffusion/jobs.py
@@ -3,14 +3,16 @@
 from dataclasses import dataclass, fields, field
 from datetime import datetime
 from enum import Enum, Flag
-from typing import Any, Deque, NamedTuple
+from typing import Any, Deque, NamedTuple, TYPE_CHECKING
 from PyQt5.QtCore import QObject, pyqtSignal
 
 from .image import Bounds, ImageCollection
 from .settings import settings
 from .style import Style
 from .util import ensure
-from . import control
+
+if TYPE_CHECKING:
+    from . import control
 
 
 class JobState(Flag):
diff --git a/tests/test_custom_workflow.py b/tests/test_custom_workflow.py
index e3fd9b177..38d52dbd0 100644
--- a/tests/test_custom_workflow.py
+++ b/tests/test_custom_workflow.py
@@ -11,6 +11,7 @@
 from ai_diffusion.custom_workflow import SortedWorkflows, CustomWorkspace
 from ai_diffusion.custom_workflow import CustomParam, ParamKind, workflow_parameters
 from ai_diffusion.image import Image, Extent
+from ai_diffusion.jobs import JobQueue
 from ai_diffusion.style import Style
 from ai_diffusion.resources import Arch
 from ai_diffusion import workflow
@@ -141,13 +142,18 @@ def test_files(tmp_path: Path):
         collection.import_file(bad_file)
 
 
+async def dummy_generate(workflow_input):
+    return None
+
+
 def test_workspace():
     connection = Connection()
     connection_workflows = {"connection1": make_dummy_graph(42)}
     connection._workflows = connection_workflows
     workflows = WorkflowCollection(connection)
 
-    workspace = CustomWorkspace(workflows)
+    jobs = JobQueue()
+    workspace = CustomWorkspace(workflows, dummy_generate, jobs)
     assert workspace.workflow_id == "connection1"
     assert workspace.workflow and workspace.workflow.id == "connection1"
     assert workspace.graph and workspace.graph.node(0).type == "ETN_Parameter"