diff --git a/src/lib.rs b/src/lib.rs
index e52e182..feb0b02 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -54,6 +54,7 @@ pub enum ByteCategory {
 }
 
 #[derive(Copy, Clone)]
+#[non_exhaustive]
 pub enum CharTable {
     AsciiOnly,
     CP437,