diff --git a/rust-toolchain b/rust-toolchain
index 65ee095..ee2f4ca 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-1.67.0
+1.68.0
diff --git a/rust-toolchain-nightly b/rust-toolchain-nightly
index ed91fac..d8b829e 100644
--- a/rust-toolchain-nightly
+++ b/rust-toolchain-nightly
@@ -1 +1 @@
-nightly-2023-02-16
+nightly-2023-03-10
diff --git a/src/lib.rs b/src/lib.rs
index 812e2a2..a04a4dc 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,7 +8,6 @@ use std::cmp::Ordering;
 use std::error::Error;
 use std::fmt::Debug;
 use std::fmt::Display;
-use std::iter::Sum;
 use std::ops::Add;
 use std::ops::AddAssign;
 use std::ops::Div;