diff --git a/src/lib.rs b/src/lib.rs
index 088948a..4e972d6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,6 +11,7 @@ pub struct Thresholds {
     pub critical: Option<NagiosRange>,
 }
 
+#[non_exhaustive]
 #[derive(Debug, PartialEq)]
 pub enum UnkownVariant {
     NotMacOS,