the PyDict_SetItem does not borrow a reference, so we need to decref
reported by Mark Hammon
diff --git a/Objects/object.c b/Objects/object.c
index 6195479..ab9d4ed 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -351,6 +351,7 @@
 		    Py_DECREF(inprogress);
 		    return NULL;
 		}
+		Py_DECREF(inprogress);
 	}
 	return inprogress;
 }