diff --git a/src/concurrency/send-sync/examples.md b/src/concurrency/send-sync/examples.md
index 8c8f92ad7b78..77f18b866527 100644
--- a/src/concurrency/send-sync/examples.md
+++ b/src/concurrency/send-sync/examples.md
@@ -28,7 +28,7 @@ Typically because of interior mutability:
 
 These types are thread-safe, but they cannot be moved to another thread:
 
-* `MutexGuard<T>`: Uses OS level primitives which must be deallocated on the
+* `MutexGuard<T: Sync>`: Uses OS level primitives which must be deallocated on the
   thread which created them.
 
 ## `!Send + !Sync`