diff --git a/core/cortex-m0/task.c b/core/cortex-m0/task.c
index 7179d05629..1d4ded513e 100644
--- a/core/cortex-m0/task.c
+++ b/core/cortex-m0/task.c
@@ -509,9 +509,8 @@ void mutex_lock(struct mutex *mtx)
 		if (mtx->lock == 0)
 			break;
 		__asm__ __volatile__("cpsie i");
-		/* TODO(crbug.com/435612, crbug.com/435611)
-		 * This discards any pending events! */
-		task_wait_event(0);  /* Contention on the mutex */
+		/* Contention on the mutex */
+		task_wait_event_mask(TASK_EVENT_MUTEX, 0);
 	}
 	mtx->lock = 2;
 	__asm__ __volatile__("cpsie i");
diff --git a/core/host/task.c b/core/host/task.c
index 9c2e650c84..8e85679890 100644
--- a/core/host/task.c
+++ b/core/host/task.c
@@ -246,10 +246,7 @@ void mutex_lock(struct mutex *mtx)
 		}
 
 		if (!value)
-			/* Contention on the mutex */
-			/* TODO(crbug.com/435612, crbug.com/435611)
-			 * This discards any pending events! */
-			task_wait_event(-1);
+			task_wait_event_mask(TASK_EVENT_MUTEX, 0);
 	} while (!value);
 
 	mtx->waiters &= ~id;