diff --git a/gix-hash/src/lib.rs b/gix-hash/src/lib.rs
index a758fb10a5f..02e7bc2420c 100644
--- a/gix-hash/src/lib.rs
+++ b/gix-hash/src/lib.rs
@@ -52,6 +52,7 @@ const SIZE_OF_SHA1_DIGEST: usize = 20;
 /// Denotes the kind of function to produce a [`ObjectId`].
 #[derive(Default, PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+#[non_exhaustive]
 pub enum Kind {
     /// The Sha1 hash with 160 bits.
     #[default]
diff --git a/gix-worktree-stream/src/protocol.rs b/gix-worktree-stream/src/protocol.rs
index 49074f22df0..7e8e1f8b44c 100644
--- a/gix-worktree-stream/src/protocol.rs
+++ b/gix-worktree-stream/src/protocol.rs
@@ -111,6 +111,7 @@ fn byte_to_mode(b: u8) -> gix_object::tree::EntryMode {
 fn hash_to_byte(h: gix_hash::Kind) -> u8 {
     match h {
         gix_hash::Kind::Sha1 => 0,
+        _ => unreachable!("BUG: not implemented for hash kind {h}"),
     }
 }