diff --git a/src/bool/ni_mp_api.rs b/src/bool/ni_mp_api.rs
index c9403df..b015b39 100644
--- a/src/bool/ni_mp_api.rs
+++ b/src/bool/ni_mp_api.rs
@@ -1,4 +1,4 @@
-use std::{cell::RefCell, sync::OnceLock};
+use std::{borrow::Borrow, cell::RefCell, sync::OnceLock};
use crate::{
backend::ModulusPowerOf2,
@@ -29,7 +29,7 @@ pub(crate) type BoolEvaluator = super::evaluator::BoolEvaluator<
thread_local! {
static BOOL_EVALUATOR: RefCell