diff --git a/embassy-sync/src/mutex.rs b/embassy-sync/src/mutex.rs
index f25f74336..7528a9f68 100644
--- a/embassy-sync/src/mutex.rs
+++ b/embassy-sync/src/mutex.rs
@@ -171,6 +171,7 @@ where
 ///
 /// Dropping it unlocks the mutex.
 #[clippy::has_significant_drop]
+#[must_use = "if unused the Mutex will immediately unlock"]
 pub struct MutexGuard<'a, M, T>
 where
     M: RawMutex,