diff --git a/Lib/multiprocessing/managers.py b/Lib/multiprocessing/managers.py
index fde0e40..8850258 100644
--- a/Lib/multiprocessing/managers.py
+++ b/Lib/multiprocessing/managers.py
@@ -410,7 +410,7 @@
             self.id_to_refcount[ident] -= 1
             if self.id_to_refcount[ident] == 0:
                 del self.id_to_obj[ident], self.id_to_refcount[ident]
-                util.debug('disposing of obj with id %d', ident)
+                util.debug('disposing of obj with id %r', ident)
         finally:
             self.mutex.release()