diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs
index d79be2944c9e3..f2c178a1ad503 100644
--- a/src/libstd/sync/mutex.rs
+++ b/src/libstd/sync/mutex.rs
@@ -30,7 +30,7 @@ use sys_common::poison::{self, TryLockError, TryLockResult, LockResult};
 ///
 /// The mutexes in this module implement a strategy called "poisoning" where a
 /// mutex is considered poisoned whenever a thread panics while holding the
-/// lock. Once a mutex is poisoned, all other threads are unable to access the
+/// mutex. Once a mutex is poisoned, all other threads are unable to access the
 /// data by default as it is likely tainted (some invariant is not being
 /// upheld).
 ///
@@ -115,7 +115,7 @@ pub struct Mutex<T: ?Sized> {
     // Note that this mutex is in a *box*, not inlined into the struct itself.
     // Once a native mutex has been used once, its address can never change (it
     // can't be moved). This mutex type can be safely moved at any time, so to
-    // ensure that the native mutex is used correctly we box the inner lock to
+    // ensure that the native mutex is used correctly we box the inner mutex to
     // give it a constant address.
     inner: Box<sys::Mutex>,
     poison: poison::Flag,
@@ -183,7 +183,7 @@ impl<T: ?Sized> Mutex<T> {
     /// Acquires a mutex, blocking the current thread until it is able to do so.
     ///
     /// This function will block the local thread until it is available to acquire
-    /// the mutex. Upon returning, the thread is the only thread with the mutex
+    /// the mutex. Upon returning, the thread is the only thread with the lock
     /// held. An RAII guard is returned to allow scoped unlock of the lock. When
     /// the guard goes out of scope, the mutex will be unlocked.
     ///
@@ -267,9 +267,9 @@ impl<T: ?Sized> Mutex<T> {
         }
     }
 
-    /// Determines whether the lock is poisoned.
+    /// Determines whether the mutex is poisoned.
     ///
-    /// If another thread is active, the lock can still become poisoned at any
+    /// If another thread is active, the mutex can still become poisoned at any
     /// time. You should not trust a `false` value for program correctness
     /// without additional synchronization.
     ///
@@ -312,7 +312,7 @@ impl<T: ?Sized> Mutex<T> {
     #[stable(feature = "mutex_into_inner", since = "1.6.0")]
     pub fn into_inner(self) -> LockResult<T> where T: Sized {
         // We know statically that there are no outstanding references to
-        // `self` so there's no need to lock the inner lock.
+        // `self` so there's no need to lock the inner mutex.
         //
         // To get the inner value, we'd like to call `data.into_inner()`,
         // but because `Mutex` impl-s `Drop`, we can't move out of it, so
@@ -353,7 +353,7 @@ impl<T: ?Sized> Mutex<T> {
     #[stable(feature = "mutex_get_mut", since = "1.6.0")]
     pub fn get_mut(&mut self) -> LockResult<&mut T> {
         // We know statically that there are no other references to `self`, so
-        // there's no need to lock the inner lock.
+        // there's no need to lock the inner mutex.
         let data = unsafe { &mut *self.data.get() };
         poison::map_result(self.poison.borrow(), |_| data )
     }