diff --git a/src/msspec/calculator.py b/src/msspec/calculator.py
index e0c2188..d7f81bb 100644
--- a/src/msspec/calculator.py
+++ b/src/msspec/calculator.py
@@ -65,7 +65,6 @@ from terminaltables.ascii_table import AsciiTable
 from msspec import iodata
 from msspec.calcio import PhagenIO
 from msspec.calcio import SpecIO
-from msspec.config import Config
 from msspec.data import electron_be
 from msspec.misc import get_call_info
 from msspec.misc import get_level_from_electron_configuration