diff --git a/src/ampform_dpd/io.py b/src/ampform_dpd/io.py
index b87252d9..73371d13 100644
--- a/src/ampform_dpd/io.py
+++ b/src/ampform_dpd/io.py
@@ -28,9 +28,6 @@
 import cloudpickle
 import sympy as sp
 from ampform.io import aslatex
-from ampform.sympy import (
-    perform_cached_doit,  # noqa: F401  # pyright:ignore[reportUnusedImport]
-)
 from tensorwaves.function.sympy import create_function, create_parametrized_function
 
 from ampform_dpd._cache import get_readable_hash, get_system_cache_directory