1 files changed, 2 insertions, 0 deletions
diff --git a/Lib/mutex.py b/Lib/mutex.py
index 2348a2e004..33baea1422 100644
--- a/Lib/mutex.py
+++ b/Lib/mutex.py
@@ -12,6 +12,8 @@ Of course, no multi-threading is implied -- hence the funny interface
 for lock, where a function is called once the lock is aquired.
 """
 
+__all__ = ["mutex"]
+
 class mutex:
     def __init__(self):
         """Create a new mutex -- initially unlocked."""