diff --git a/library/std/src/sys/windows/mutex.rs b/library/std/src/sys/windows/mutex.rs
index 72a0993d94d..12c5ea741f9 100644
--- a/library/std/src/sys/windows/mutex.rs
+++ b/library/std/src/sys/windows/mutex.rs
@@ -23,8 +23,6 @@ pub struct Mutex {
 }
 
 // Windows SRW Locks are movable (while not borrowed).
-// ReentrantMutexes (in Inner) are not, but those are stored indirectly through
-// a Box, so do not move when the Mutex it self is moved.
 pub type MovableMutex = Mutex;
 
 unsafe impl Send for Mutex {}