diff --git a/modal/_container_io_manager.py b/modal/_container_io_manager.py
index 051157df1..4007b8cde 100644
--- a/modal/_container_io_manager.py
+++ b/modal/_container_io_manager.py
@@ -56,6 +56,20 @@ class IOContext:
     function_call_ids: List[str]
     finalized_function: FinalizedFunction
 
+    def __init__(
+        self,
+        input_ids: List[str],
+        function_call_ids: List[str],
+        finalized_function: FinalizedFunction,
+        deserialized_args: List,
+        is_batched: bool,
+    ):
+        self.input_ids = input_ids
+        self.function_call_ids = function_call_ids
+        self.finalized_function = finalized_function
+        self.deserialized_args = deserialized_args
+        self.is_batched = is_batched
+
     @classmethod
     async def create(
         cls,
@@ -64,31 +78,28 @@ async def create(
         inputs: List[Tuple[str, str, api_pb2.FunctionInput]],
         is_batched: bool,
     ) -> "IOContext":
-        self = cls.__new__(cls)
         assert len(inputs) >= 1 if is_batched else len(inputs) == 1
-        self.input_ids, self.function_call_ids, inputs = zip(*inputs)
-        self.inputs = await asyncio.gather(
-            *[self._populate_input_blobs(container_io_manager, input) for input in inputs]
-        )
+        input_ids, function_call_ids, inputs = zip(*inputs)
+
+        async def _populate_input_blobs(container_io_manager: "_ContainerIOManager", input: api_pb2.FunctionInput):
+            # If we got a pointer to a blob, download it from S3.
+            if input.WhichOneof("args_oneof") == "args_blob_id":
+                args = await container_io_manager.blob_download(input.args_blob_id)
+                # Mutating
+                input.ClearField("args_blob_id")
+                input.args = args
+
+            return input
+
+        inputs = await asyncio.gather(*[_populate_input_blobs(container_io_manager, input) for input in inputs])
         # check every input in batch executes the same function
-        method_name = self.inputs[0].method_name
-        assert all(method_name == input.method_name for input in self.inputs)
-        self.finalized_function = finalized_functions[method_name]
-        self.deserialized_args = [
+        method_name = inputs[0].method_name
+        assert all(method_name == input.method_name for input in inputs)
+        finalized_function = finalized_functions[method_name]
+        deserialized_args = [
             container_io_manager.deserialize(input.args) if input.args else ((), {}) for input in inputs
         ]
-        self.is_batched = is_batched
-        return self
-
-    async def _populate_input_blobs(self, container_io_manager: "_ContainerIOManager", input: api_pb2.FunctionInput):
-        # If we got a pointer to a blob, download it from S3.
-        if input.WhichOneof("args_oneof") == "args_blob_id":
-            args = await container_io_manager.blob_download(input.args_blob_id)
-            # Mutating
-            input.ClearField("args_blob_id")
-            input.args = args
-
-        return input
+        return cls(input_ids, function_call_ids, finalized_function, deserialized_args, is_batched)
 
     def _args_and_kwargs(self):
         if not self.is_batched: