diff --git a/zebra-chain/src/sapling/tree.rs b/zebra-chain/src/sapling/tree.rs
index 5fd939a2..a111c3ac 100644
--- a/zebra-chain/src/sapling/tree.rs
+++ b/zebra-chain/src/sapling/tree.rs
@@ -54,7 +54,7 @@ pub struct Position(pub(crate) u64);
 /// Sapling Note Commitment Tree
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
 #[cfg_attr(test, derive(Arbitrary))]
-pub struct SaplingNoteCommitmentTree;
+struct SaplingNoteCommitmentTree;
 
 /// Sapling note commitment tree root node hash.
 ///