diff --git a/csst_common/status.py b/csst_common/status.py
index 11272871920246e0a678ef3587115a8b1b7df617..b256806acdcf16bbe81e11a38fa18edc601e6232 100644
--- a/csst_common/status.py
+++ b/csst_common/status.py
@@ -10,7 +10,7 @@ Modified-History:
     2022-10-07, Bo Zhang, added Numpydoc docstring
 """
 from enum import IntEnum
-from typing import Optional
+from typing import Optional, Any
 
 
 class CsstStatus(IntEnum):
@@ -44,16 +44,16 @@ class CsstResult:
     def __init__(
         self,
         status: CsstStatus = CsstStatus.ERROR,
-        files: Optional = None,
-        **output,
+        files: Optional[list] = None,
+        **output: Any,
     ):
         if files is None:
             files = []
         assert isinstance(status, CsstStatus)
         assert type(files) is list
-        self.status = status
-        self.files = files
-        self.output = output
+        self.status: CsstStatus = status
+        self.files: Optional[list] = files
+        self.output: dict = output
 
     def __repr__(self):
         return f""" <CsstResult status={self.status}>