diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 86b8f8a..6e68eae 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -2,5 +2,5 @@
 # SPDX-License-Identifier: CC0-1.0
 
 [toolchain]
-# We are on nightly so that we can use the `bigint_helper_methods` feature.
+# We are on nightly so that we can use the `widening_mul` feature.
 channel = "nightly"
diff --git a/src/lib.rs b/src/lib.rs
index 5e9c0b9..3f548d2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,7 @@
 // SPDX-FileCopyrightText: 2025 Severen Redwood <sev@severen.dev>
 // SPDX-License-Identifier: GPL-3.0-or-later
 
-#![feature(bigint_helper_methods)]
+#![feature(widening_mul)]
 
 use crate::syntax::Expr;