diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index c9aa23fc4af1..fd1e3e0f75b0 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -1092,7 +1092,7 @@ pub fn get_mut(this: &mut Self) -> Option<&mut T> {
     /// # Safety
     ///
     /// If any other `Rc` or [`Weak`] pointers to the same allocation exist, then
-    /// they must be must not be dereferenced or have active borrows for the duration
+    /// they must not be dereferenced or have active borrows for the duration
     /// of the returned borrow, and their inner type must be exactly the same as the
     /// inner type of this Rc (including lifetimes). This is trivially the case if no
     /// such pointers exist, for example immediately after `Rc::new`.
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs
index 9bc9182f7b53..f20486ca9e4d 100644
--- a/library/alloc/src/sync.rs
+++ b/library/alloc/src/sync.rs
@@ -1733,7 +1733,7 @@ pub fn get_mut(this: &mut Self) -> Option<&mut T> {
     /// # Safety
     ///
     /// If any other `Arc` or [`Weak`] pointers to the same allocation exist, then
-    /// they must be must not be dereferenced or have active borrows for the duration
+    /// they must not be dereferenced or have active borrows for the duration
     /// of the returned borrow, and their inner type must be exactly the same as the
     /// inner type of this Rc (including lifetimes). This is trivially the case if no
     /// such pointers exist, for example immediately after `Arc::new`.