diff --git a/zcash_client_backend/src/data_api.rs b/zcash_client_backend/src/data_api.rs
index b20ced7ae..098ad9e61 100644
--- a/zcash_client_backend/src/data_api.rs
+++ b/zcash_client_backend/src/data_api.rs
@@ -867,6 +867,16 @@ pub trait WalletCommitmentTrees {
         Error = Self::Error,
     >;
 
+    /// Returns the depth of the checkpoint in the tree that can be used to create a witness at the
+    /// anchor having the given number of confirmations.
+    ///
+    /// This assumes that at any time a note is added to the tree, a checkpoint is created for the
+    /// end of the block in which that note was discovered.
+    fn get_checkpoint_depth(
+        &self,
+        min_confirmations: NonZeroU32,
+    ) -> Result<usize, ShardTreeError<Self::Error>>;
+
     fn with_sapling_tree_mut<F, A, E>(&mut self, callback: F) -> Result<A, E>
     where
         for<'a> F: FnMut(
@@ -1182,5 +1192,12 @@ pub mod testing {
 
             Ok(())
         }
+
+        fn get_checkpoint_depth(
+            &self,
+            min_confirmations: NonZeroU32,
+        ) -> Result<usize, ShardTreeError<Self::Error>> {
+            Ok(usize::try_from(u32::from(min_confirmations) - 1).unwrap())
+        }
     }
 }
diff --git a/zcash_client_backend/src/data_api/wallet.rs b/zcash_client_backend/src/data_api/wallet.rs
index da820e729..71d050369 100644
--- a/zcash_client_backend/src/data_api/wallet.rs
+++ b/zcash_client_backend/src/data_api/wallet.rs
@@ -488,6 +488,8 @@ where
     // are no possible transparent inputs, so we ignore those
     let mut builder = Builder::new(params.clone(), proposal.min_target_height(), None);
 
+    let checkpoint_depth = wallet_db.get_checkpoint_depth(min_confirmations)?;
+
     wallet_db.with_sapling_tree_mut::<_, _, Error<_, _, _, _, _>>(|sapling_tree| {
         for selected in proposal.sapling_inputs() {
             let (note, key, merkle_path) = select_key_for_note(
@@ -495,7 +497,7 @@ where
                 selected,
                 usk.sapling(),
                 &dfvk,
-                usize::try_from(u32::from(min_confirmations) - 1).unwrap(),
+                checkpoint_depth,
             )?
             .ok_or(Error::NoteMismatch(selected.note_id))?;
 
diff --git a/zcash_client_sqlite/src/lib.rs b/zcash_client_sqlite/src/lib.rs
index 22f0ff8c6..3c30f3f6b 100644
--- a/zcash_client_sqlite/src/lib.rs
+++ b/zcash_client_sqlite/src/lib.rs
@@ -44,7 +44,10 @@ use std::{
 };
 
 use incrementalmerkletree::Position;
-use shardtree::{error::ShardTreeError, ShardTree};
+use shardtree::{
+    error::{QueryError, ShardTreeError},
+    ShardTree,
+};
 use zcash_primitives::{
     block::BlockHash,
     consensus::{self, BlockHeight},
@@ -89,7 +92,7 @@ pub mod serialization;
 
 pub mod wallet;
 use wallet::{
-    commitment_tree::{self, put_shard_roots},
+    commitment_tree::{self, get_checkpoint_depth, put_shard_roots},
     SubtreeScanProgress,
 };
 
@@ -795,6 +798,15 @@ impl<P: consensus::Parameters> WalletCommitmentTrees for WalletDb<rusqlite::Conn
             .map_err(|e| ShardTreeError::Storage(commitment_tree::Error::Query(e)))?;
         Ok(())
     }
+
+    fn get_checkpoint_depth(
+        &self,
+        min_confirmations: NonZeroU32,
+    ) -> Result<usize, ShardTreeError<Self::Error>> {
+        get_checkpoint_depth(&self.conn, SAPLING_TABLES_PREFIX, min_confirmations)
+            .map_err(|e| ShardTreeError::Storage(commitment_tree::Error::Query(e)))?
+            .ok_or(ShardTreeError::Query(QueryError::CheckpointPruned))
+    }
 }
 
 impl<'conn, P: consensus::Parameters> WalletCommitmentTrees for WalletDb<SqlTransaction<'conn>, P> {
@@ -835,6 +847,18 @@ impl<'conn, P: consensus::Parameters> WalletCommitmentTrees for WalletDb<SqlTran
             roots,
         )
     }
+
+    fn get_checkpoint_depth(
+        &self,
+        min_confirmations: NonZeroU32,
+    ) -> Result<usize, ShardTreeError<Self::Error>> {
+        get_checkpoint_depth(self.conn.0, SAPLING_TABLES_PREFIX, min_confirmations)
+            .map_err(|e| ShardTreeError::Storage(commitment_tree::Error::Query(e)))?
+            // `CheckpointPruned` is perhaps a little misleading; in this case it's that
+            // the chain tip is unknown, but if that were the case we should never have been
+            // calling this anyway.
+            .ok_or(ShardTreeError::Query(QueryError::CheckpointPruned))
+    }
 }
 
 /// A handle for the SQLite block source.
diff --git a/zcash_client_sqlite/src/wallet/commitment_tree.rs b/zcash_client_sqlite/src/wallet/commitment_tree.rs
index f90b135be..f05ab043c 100644
--- a/zcash_client_sqlite/src/wallet/commitment_tree.rs
+++ b/zcash_client_sqlite/src/wallet/commitment_tree.rs
@@ -4,6 +4,7 @@ use std::{
     error, fmt,
     io::{self, Cursor},
     marker::PhantomData,
+    num::NonZeroU32,
     ops::Range,
     sync::Arc,
 };
@@ -20,6 +21,8 @@ use zcash_primitives::{consensus::BlockHeight, merkle_tree::HashSer};
 
 use crate::serialization::{read_shard, write_shard};
 
+use super::scan_queue_extrema;
+
 /// Errors that can appear in SQLite-back [`ShardStore`] implementation operations.
 #[derive(Debug)]
 pub enum Error {
@@ -724,8 +727,8 @@ pub(crate) fn get_checkpoint(
         .query_row(
             &format!(
                 "SELECT position
-            FROM {}_tree_checkpoints
-            WHERE checkpoint_id = ?",
+                 FROM {}_tree_checkpoints
+                 WHERE checkpoint_id = ?",
                 table_prefix
             ),
             [u32::from(checkpoint_id)],
@@ -747,6 +750,33 @@ pub(crate) fn get_checkpoint(
         .transpose()
 }
 
+pub(crate) fn get_checkpoint_depth(
+    conn: &rusqlite::Connection,
+    table_prefix: &'static str,
+    min_confirmations: NonZeroU32,
+) -> Result<Option<usize>, rusqlite::Error> {
+    scan_queue_extrema(conn)?
+        .map(|(_, max)| max)
+        .map(|chain_tip| {
+            let max_checkpoint_height =
+                u32::from(chain_tip).saturating_sub(u32::from(min_confirmations) - 1);
+
+            // We exclude from consideration all checkpoints having heights greater than the maximum
+            // checkpoint height. The checkpoint depth is the number of excluded checkpoints + 1.
+            conn.query_row(
+                &format!(
+                    "SELECT COUNT(*) 
+                     FROM {}_tree_checkpoints
+                     WHERE checkpoint_id > :max_checkpoint_height",
+                    table_prefix
+                ),
+                named_params![":max_checkpoint_height": max_checkpoint_height],
+                |row| row.get::<_, usize>(0).map(|s| s + 1),
+            )
+        })
+        .transpose()
+}
+
 pub(crate) fn get_checkpoint_at_depth(
     conn: &rusqlite::Connection,
     table_prefix: &'static str,