diff --git a/Lib/_threading_local.py b/Lib/_threading_local.py
--- a/Lib/_threading_local.py
+++ b/Lib/_threading_local.py
@@ -221,7 +221,13 @@
             lock.release()
 
     def __del__(self):
-        import threading
+        try:
+            import threading
+        except ImportError:
+            import sys
+            if '_dummy_threading' in sys.modules:
+                return
+            raise
 
         key = object.__getattribute__(self, '_local__key')