diff --git a/api/onnx_web/chain/blend_grid.py b/api/onnx_web/chain/blend_grid.py
index 19b1eca2..19af2fbd 100644
--- a/api/onnx_web/chain/blend_grid.py
+++ b/api/onnx_web/chain/blend_grid.py
@@ -3,7 +3,7 @@ from typing import List, Optional
 
 from PIL import Image
 
-from ..params import ImageParams, StageParams
+from ..params import ImageParams, SizeChart, StageParams
 from ..server import ServerContext
 from ..worker import ProgressCallback, WorkerContext
 from .stage import BaseStage
@@ -12,6 +12,8 @@ logger = getLogger(__name__)
 
 
 class BlendGridStage(BaseStage):
+    max_tile = SizeChart.max
+
     def run(
         self,
         _worker: WorkerContext,
diff --git a/api/onnx_web/chain/persist_disk.py b/api/onnx_web/chain/persist_disk.py
index 890e6589..7d9a0fe6 100644
--- a/api/onnx_web/chain/persist_disk.py
+++ b/api/onnx_web/chain/persist_disk.py
@@ -4,7 +4,7 @@ from typing import List, Optional
 from PIL import Image
 
 from ..output import save_image
-from ..params import ImageParams, Size, StageParams
+from ..params import ImageParams, Size, SizeChart, StageParams
 from ..server import ServerContext
 from ..worker import WorkerContext
 from .stage import BaseStage
@@ -13,6 +13,8 @@ logger = getLogger(__name__)
 
 
 class PersistDiskStage(BaseStage):
+    max_tile = SizeChart.max
+
     def run(
         self,
         _worker: WorkerContext,