diff --git a/src/caosadvancedtools/table_json_conversion/convert.py b/src/caosadvancedtools/table_json_conversion/convert.py
index 84e3b9547289a5afdc1553dfab6f7f1e19a1a0fb..1f87bc7f5fa67b4597b320770469e9cca71fbb44 100644
--- a/src/caosadvancedtools/table_json_conversion/convert.py
+++ b/src/caosadvancedtools/table_json_conversion/convert.py
@@ -28,7 +28,7 @@ import sys
 from functools import reduce
 from operator import getitem
 from types import SimpleNamespace
-from typing import Any, BinaryIO, Callable, TextIO, Union
+from typing import Any, BinaryIO, Callable, TextIO, Union, Optional
 from warnings import warn
 
 import jsonschema
@@ -430,7 +430,7 @@ class XLSXConverter:
         try:
             subschema = self._get_subschema(path)
         except KeyError as e:
-            raise KeyError("There is no entry in the schema that corresponds to this column.")
+            raise KeyError("There is no entry in the schema that corresponds to this column.") from e
         # Array handling only if schema says it's an array.
         if subschema.get("type") == "array":
             array_type = subschema["items"]["type"]