diff --git a/Cargo.toml b/Cargo.toml
index 6b2e0e94a..57209ab1a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -156,3 +156,6 @@ zip32 = "0.1.1"
 lto = true
 panic = 'abort'
 codegen-units = 1
+
+[workspace.lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(zcash_unstable, values("zfuture"))'] }
diff --git a/components/zip321/Cargo.toml b/components/zip321/Cargo.toml
index 33052c2a6..013f824e9 100644
--- a/components/zip321/Cargo.toml
+++ b/components/zip321/Cargo.toml
@@ -22,7 +22,14 @@ nom = "7"
 base64.workspace = true
 percent-encoding.workspace = true
 
+# - Test dependencies
+proptest = { workspace = true, optional = true }
+
 [dev-dependencies]
 zcash_address = { workspace = true, features = ["test-dependencies"] }
 zcash_protocol = { workspace = true, features = ["test-dependencies"] }
 proptest.workspace = true
+
+[features]
+## Exposes APIs that are useful for testing, such as `proptest` strategies.
+test-dependencies = ["dep:proptest"]
diff --git a/zcash_client_backend/src/scan.rs b/zcash_client_backend/src/scan.rs
index 0eb9abedb..74461d3dd 100644
--- a/zcash_client_backend/src/scan.rs
+++ b/zcash_client_backend/src/scan.rs
@@ -56,6 +56,7 @@ pub(crate) trait Decryptor<D: BatchDomain, Output> {
 }
 
 /// A decryptor of outputs as encoded in transactions.
+#[allow(dead_code)]
 pub(crate) struct FullDecryptor;
 
 impl<D: BatchDomain, Output: ShieldedOutput<D, ENC_CIPHERTEXT_SIZE>> Decryptor<D, Output>
@@ -200,6 +201,7 @@ impl<Item: Task> Tasks<Item> for () {
 ///
 /// This struct implements `DynamicUsage` without any item bounds, but that works because
 /// it only implements `Tasks` for items that implement `DynamicUsage`.
+#[allow(dead_code)]
 pub(crate) struct WithUsage {
     // The current heap usage for all running tasks.
     running_usage: Arc<AtomicUsize>,
diff --git a/zcash_client_sqlite/src/wallet/scanning.rs b/zcash_client_sqlite/src/wallet/scanning.rs
index 64dede7e9..5e236ac2a 100644
--- a/zcash_client_sqlite/src/wallet/scanning.rs
+++ b/zcash_client_sqlite/src/wallet/scanning.rs
@@ -1,6 +1,5 @@
 use incrementalmerkletree::{Address, Position};
 use rusqlite::{self, named_params, types::Value, OptionalExtension};
-use shardtree::error::ShardTreeError;
 use std::cmp::{max, min};
 use std::collections::BTreeSet;
 use std::ops::Range;
@@ -18,7 +17,7 @@ use zcash_primitives::consensus::{self, BlockHeight, NetworkUpgrade};
 
 use crate::{
     error::SqliteClientError,
-    wallet::{block_height_extrema, commitment_tree, init::WalletMigrationError},
+    wallet::{block_height_extrema, init::WalletMigrationError},
     PRUNING_DEPTH, SAPLING_TABLES_PREFIX, VERIFY_LOOKAHEAD,
 };
 
@@ -119,8 +118,6 @@ pub(crate) fn insert_queue_entries<'a>(
 pub(crate) trait WalletError {
     fn db_error(err: rusqlite::Error) -> Self;
     fn corrupt(message: String) -> Self;
-    fn chain_height_unknown() -> Self;
-    fn commitment_tree(err: ShardTreeError<commitment_tree::Error>) -> Self;
 }
 
 impl WalletError for SqliteClientError {
@@ -131,14 +128,6 @@ impl WalletError for SqliteClientError {
     fn corrupt(message: String) -> Self {
         SqliteClientError::CorruptedData(message)
     }
-
-    fn chain_height_unknown() -> Self {
-        SqliteClientError::ChainHeightUnknown
-    }
-
-    fn commitment_tree(err: ShardTreeError<commitment_tree::Error>) -> Self {
-        SqliteClientError::CommitmentTree(err)
-    }
 }
 
 impl WalletError for WalletMigrationError {
@@ -149,16 +138,6 @@ impl WalletError for WalletMigrationError {
     fn corrupt(message: String) -> Self {
         WalletMigrationError::CorruptedData(message)
     }
-
-    fn chain_height_unknown() -> Self {
-        WalletMigrationError::CorruptedData(
-            "Wallet migration requires a valid account birthday.".to_owned(),
-        )
-    }
-
-    fn commitment_tree(err: ShardTreeError<commitment_tree::Error>) -> Self {
-        WalletMigrationError::CommitmentTree(err)
-    }
 }
 
 pub(crate) fn replace_queue_entries<E: WalletError>(