diff --git a/src/guard.rs b/src/guard.rs
index 0482aeb87..c16229f49 100644
--- a/src/guard.rs
+++ b/src/guard.rs
@@ -195,7 +195,7 @@ impl Guard for NotGuard {
     }
 
     fn clone_guard(&self) -> Box<dyn Guard> {
-        self.0.clone_guard()
+        Box::new(NotGuard(self.0.clone_guard()))
     }
 }