diff --git a/library/std/src/sync/mpmc/array.rs b/library/std/src/sync/mpmc/array.rs
index 5778547ee02..4db7b4990b9 100644
--- a/library/std/src/sync/mpmc/array.rs
+++ b/library/std/src/sync/mpmc/array.rs
@@ -169,7 +169,7 @@ impl<T> Channel<T> {
                     }
                     Err(_) => {
                         backoff.spin();
-                        tail = self.load(Ordering::Relaxed);
+                        tail = self.tail.load(Ordering::Relaxed);
                     }
                 }
             } else if stamp.wrapping_add(self.one_lap) == tail + 1 {
@@ -250,7 +250,7 @@ impl<T> Channel<T> {
                         token.array.stamp = head.wrapping_add(self.one_lap);
                         return true;
                     }
-                    Err(h) => {
+                    Err(_) => {
                         backoff.spin();
                         head = self.head.load(Ordering::Relaxed);
                     }
diff --git a/library/std/src/sync/mpmc/context.rs b/library/std/src/sync/mpmc/context.rs
index dea6880017d..3077c0ee375 100644
--- a/library/std/src/sync/mpmc/context.rs
+++ b/library/std/src/sync/mpmc/context.rs
@@ -1,7 +1,6 @@
 //! Thread-local channel context.
 
 use super::select::Selected;
-use super::utils::Backoff;
 
 use crate::cell::Cell;
 use crate::ptr;
diff --git a/library/std/src/sync/mpmc/list.rs b/library/std/src/sync/mpmc/list.rs
index 22b6b1133ae..2d5b2fb3b23 100644
--- a/library/std/src/sync/mpmc/list.rs
+++ b/library/std/src/sync/mpmc/list.rs
@@ -350,7 +350,7 @@ impl<T> Channel<T> {
                     token.list.offset = offset;
                     return true;
                 },
-                Err(h) => {
+                Err(_) => {
                     backoff.spin();
                     head = self.head.index.load(Ordering::Acquire);
                     block = self.head.block.load(Ordering::Acquire);
diff --git a/library/std/src/sync/mpmc/utils.rs b/library/std/src/sync/mpmc/utils.rs
index 85cf5dd2441..d0904b4b94c 100644
--- a/library/std/src/sync/mpmc/utils.rs
+++ b/library/std/src/sync/mpmc/utils.rs
@@ -111,7 +111,7 @@ impl Backoff {
     #[inline]
     pub fn spin(&self) {
         let step = self.step.get().min(SPIN_LIMIT);
-        for _ in 0..step.pow(2)  {
+        for _ in 0..step.pow(2) {
             crate::hint::spin_loop();
         }