diff --git a/hydra/_internal/callbacks.py b/hydra/_internal/callbacks.py
index a9d45d286b..cc38b8aa94 100644
--- a/hydra/_internal/callbacks.py
+++ b/hydra/_internal/callbacks.py
@@ -1,6 +1,6 @@
 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
 import warnings
-from typing import Any, Dict, List, Optional, TYPE_CHECKING
+from typing import TYPE_CHECKING, Any, Dict, List, Optional
 
 from omegaconf import DictConfig, OmegaConf
 
@@ -28,6 +28,8 @@ def __init__(self) -> None:
 
 
 class Callbacks:
+    callbacks: List[Any]
+
     def __init__(
         self, config: Optional[DictConfig] = None, check_cache: bool = True
     ) -> None:
diff --git a/hydra/experimental/callback.py b/hydra/experimental/callback.py
index 0c77cc068e..3187e38a9e 100644
--- a/hydra/experimental/callback.py
+++ b/hydra/experimental/callback.py
@@ -2,11 +2,11 @@
 import logging
 from typing import Any, List, Optional
 
+from omegaconf import DictConfig
+
 from hydra.core.utils import JobReturn
 from hydra.types import TaskFunction
 
-from omegaconf import DictConfig
-
 logger = logging.getLogger(__name__)
 
 
diff --git a/hydra/experimental/callbacks.py b/hydra/experimental/callbacks.py
index 9b75c2e22e..c836f9ef40 100644
--- a/hydra/experimental/callbacks.py
+++ b/hydra/experimental/callbacks.py
@@ -6,7 +6,7 @@
 from pathlib import Path
 from typing import Any, List, Optional
 
-from omegaconf import DictConfig, flag_override, OmegaConf
+from omegaconf import DictConfig, OmegaConf, flag_override
 
 from hydra.core.global_hydra import GlobalHydra
 from hydra.core.utils import JobReturn, JobStatus