diff --git a/api/onnx_web/chain/pipeline.py b/api/onnx_web/chain/pipeline.py
index c52078b1..b1f01ced 100644
--- a/api/onnx_web/chain/pipeline.py
+++ b/api/onnx_web/chain/pipeline.py
@@ -33,6 +33,8 @@ class ChainProgress:
         self.parent = parent
         self.step = start
         self.total = 0
+        self.stage = 0
+        self.tile = 0
 
     def __call__(self, step: int, timestep: int, latents: Any) -> None:
         if step < self.step:
diff --git a/api/onnx_web/worker/context.py b/api/onnx_web/worker/context.py
index 83e3cfd0..a5bd10d7 100644
--- a/api/onnx_web/worker/context.py
+++ b/api/onnx_web/worker/context.py
@@ -57,6 +57,7 @@ class WorkerContext:
         self.initial_retries = retries
         self.retries = retries
         self.timeout = timeout
+        self.callback = None
 
     def start(self, job: JobCommand) -> None:
         # set job name and type