diff --git a/crates/core/src/spk_client.rs b/crates/core/src/spk_client.rs
index 1aceae5bb..2c84fdf86 100644
--- a/crates/core/src/spk_client.rs
+++ b/crates/core/src/spk_client.rs
@@ -4,7 +4,7 @@ use crate::{
     collections::BTreeMap,
     CheckPoint, ConfirmationBlockTime, Indexed,
 };
-use bitcoin::{OutPoint, Script, ScriptBuf, Txid};
+use bitcoin::{BlockHash, OutPoint, Script, ScriptBuf, Txid};
 
 type InspectSync<I> = dyn FnMut(SyncItem<I>, SyncProgress) + Send + 'static;
 
@@ -88,11 +88,11 @@ impl SyncProgress {
 
 /// Builds a [`SyncRequest`].
 #[must_use]
-pub struct SyncRequestBuilder<I = ()> {
-    inner: SyncRequest<I>,
+pub struct SyncRequestBuilder<I = (), B = BlockHash> {
+    inner: SyncRequest<I, B>,
 }
 
-impl<I> Default for SyncRequestBuilder<I> {
+impl<I, B> Default for SyncRequestBuilder<I, B> {
     fn default() -> Self {
         Self {
             inner: Default::default(),
@@ -107,11 +107,11 @@ impl SyncRequestBuilder<()> {
     }
 }
 
-impl<I> SyncRequestBuilder<I> {
+impl<I, B> SyncRequestBuilder<I, B> {
     /// Set the initial chain tip for the sync request.
     ///
     /// This is used to update [`LocalChain`](../../bdk_chain/local_chain/struct.LocalChain.html).
-    pub fn chain_tip(mut self, cp: CheckPoint) -> Self {
+    pub fn chain_tip(mut self, cp: CheckPoint<B>) -> Self {
         self.inner.chain_tip = Some(cp);
         self
     }
@@ -124,6 +124,7 @@ impl<I> SyncRequestBuilder<I> {
     /// [`KeychainTxOutIndex`](../../bdk_chain/indexer/keychain_txout/struct.KeychainTxOutIndex.html).
     ///
     /// ```rust
+    /// # use bdk_chain::bitcoin::BlockHash;
     /// # use bdk_chain::spk_client::SyncRequest;
     /// # use bdk_chain::indexer::keychain_txout::KeychainTxOutIndex;
     /// # use bdk_chain::miniscript::{Descriptor, DescriptorPublicKey};
@@ -141,7 +142,7 @@ impl<I> SyncRequestBuilder<I> {
     /// let (newly_revealed_spks, _changeset) = indexer
     ///     .reveal_to_target("descriptor_a", 21)
     ///     .expect("keychain must exist");
-    /// let _request = SyncRequest::builder()
+    /// let _request: SyncRequest<u32, BlockHash> = SyncRequest::builder()
     ///     .spks_with_indexes(newly_revealed_spks)
     ///     .build();
     ///
@@ -149,7 +150,7 @@ impl<I> SyncRequestBuilder<I> {
     /// // keychains. Each spk will be indexed with `(&'static str, u32)` where `&'static str` is
     /// // the keychain identifier and `u32` is the derivation index.
     /// let all_revealed_spks = indexer.revealed_spks(..);
-    /// let _request = SyncRequest::builder()
+    /// let _request: SyncRequest<(&str, u32), BlockHash> = SyncRequest::builder()
     ///     .spks_with_indexes(all_revealed_spks)
     ///     .build();
     /// # Ok::<_, bdk_chain::keychain_txout::InsertDescriptorError<_>>(())
@@ -181,7 +182,7 @@ impl<I> SyncRequestBuilder<I> {
     }
 
     /// Build the [`SyncRequest`].
-    pub fn build(self) -> SyncRequest<I> {
+    pub fn build(self) -> SyncRequest<I, B> {
         self.inner
     }
 }
@@ -209,8 +210,8 @@ impl<I> SyncRequestBuilder<I> {
 ///     .build();
 /// ```
 #[must_use]
-pub struct SyncRequest<I = ()> {
-    chain_tip: Option<CheckPoint>,
+pub struct SyncRequest<I = (), B = BlockHash> {
+    chain_tip: Option<CheckPoint<B>>,
     spks: VecDeque<(I, ScriptBuf)>,
     spks_consumed: usize,
     txids: VecDeque<Txid>,
@@ -220,7 +221,7 @@ pub struct SyncRequest<I = ()> {
     inspect: Box<InspectSync<I>>,
 }
 
-impl<I> Default for SyncRequest<I> {
+impl<I, B> Default for SyncRequest<I, B> {
     fn default() -> Self {
         Self {
             chain_tip: None,
@@ -235,15 +236,15 @@ impl<I> Default for SyncRequest<I> {
     }
 }
 
-impl<I> From<SyncRequestBuilder<I>> for SyncRequest<I> {
-    fn from(builder: SyncRequestBuilder<I>) -> Self {
+impl<I, B> From<SyncRequestBuilder<I, B>> for SyncRequest<I, B> {
+    fn from(builder: SyncRequestBuilder<I, B>) -> Self {
         builder.inner
     }
 }
 
-impl<I> SyncRequest<I> {
+impl<I, B> SyncRequest<I, B> {
     /// Start building a [`SyncRequest`].
-    pub fn builder() -> SyncRequestBuilder<I> {
+    pub fn builder() -> SyncRequestBuilder<I, B> {
         SyncRequestBuilder {
             inner: Default::default(),
         }
@@ -262,7 +263,7 @@ impl<I> SyncRequest<I> {
     }
 
     /// Get the chain tip [`CheckPoint`] of this request (if any).
-    pub fn chain_tip(&self) -> Option<CheckPoint> {
+    pub fn chain_tip(&self) -> Option<CheckPoint<B>> {
         self.chain_tip.clone()
     }
 
@@ -298,17 +299,17 @@ impl<I> SyncRequest<I> {
 
     /// Iterate over [`ScriptBuf`]s contained in this request.
     pub fn iter_spks(&mut self) -> impl ExactSizeIterator<Item = ScriptBuf> + '_ {
-        SyncIter::<I, ScriptBuf>::new(self)
+        SyncIter::<I, B, ScriptBuf>::new(self)
     }
 
     /// Iterate over [`Txid`]s contained in this request.
     pub fn iter_txids(&mut self) -> impl ExactSizeIterator<Item = Txid> + '_ {
-        SyncIter::<I, Txid>::new(self)
+        SyncIter::<I, B, Txid>::new(self)
     }
 
     /// Iterate over [`OutPoint`]s contained in this request.
     pub fn iter_outpoints(&mut self) -> impl ExactSizeIterator<Item = OutPoint> + '_ {
-        SyncIter::<I, OutPoint>::new(self)
+        SyncIter::<I, B, OutPoint>::new(self)
     }
 
     fn _call_inspect(&mut self, item: SyncItem<I>) {
@@ -322,14 +323,14 @@ impl<I> SyncRequest<I> {
 /// See also [`SyncRequest`].
 #[must_use]
 #[derive(Debug)]
-pub struct SyncResult<A = ConfirmationBlockTime> {
+pub struct SyncResult<B = BlockHash, A = ConfirmationBlockTime> {
     /// Relevant transaction data discovered during the scan.
     pub tx_update: crate::TxUpdate<A>,
     /// Changes to the chain discovered during the scan.
-    pub chain_update: Option<CheckPoint>,
+    pub chain_update: Option<CheckPoint<B>>,
 }
 
-impl<A> Default for SyncResult<A> {
+impl<B, A> Default for SyncResult<B, A> {
     fn default() -> Self {
         Self {
             tx_update: Default::default(),
@@ -340,11 +341,11 @@ impl<A> Default for SyncResult<A> {
 
 /// Builds a [`FullScanRequest`].
 #[must_use]
-pub struct FullScanRequestBuilder<K> {
-    inner: FullScanRequest<K>,
+pub struct FullScanRequestBuilder<K, B = BlockHash> {
+    inner: FullScanRequest<K, B>,
 }
 
-impl<K> Default for FullScanRequestBuilder<K> {
+impl<K, B> Default for FullScanRequestBuilder<K, B> {
     fn default() -> Self {
         Self {
             inner: Default::default(),
@@ -352,11 +353,11 @@ impl<K> Default for FullScanRequestBuilder<K> {
     }
 }
 
-impl<K: Ord> FullScanRequestBuilder<K> {
+impl<K: Ord, B> FullScanRequestBuilder<K, B> {
     /// Set the initial chain tip for the full scan request.
     ///
     /// This is used to update [`LocalChain`](../../bdk_chain/local_chain/struct.LocalChain.html).
-    pub fn chain_tip(mut self, tip: CheckPoint) -> Self {
+    pub fn chain_tip(mut self, tip: CheckPoint<B>) -> Self {
         self.inner.chain_tip = Some(tip);
         self
     }
@@ -383,7 +384,7 @@ impl<K: Ord> FullScanRequestBuilder<K> {
     }
 
     /// Build the [`FullScanRequest`].
-    pub fn build(self) -> FullScanRequest<K> {
+    pub fn build(self) -> FullScanRequest<K, B> {
         self.inner
     }
 }
@@ -396,19 +397,19 @@ impl<K: Ord> FullScanRequestBuilder<K> {
 /// used scripts is not known. The full scan process also updates the chain from the given
 /// [`chain_tip`](FullScanRequestBuilder::chain_tip) (if provided).
 #[must_use]
-pub struct FullScanRequest<K> {
-    chain_tip: Option<CheckPoint>,
+pub struct FullScanRequest<K, B = BlockHash> {
+    chain_tip: Option<CheckPoint<B>>,
     spks_by_keychain: BTreeMap<K, Box<dyn Iterator<Item = Indexed<ScriptBuf>> + Send>>,
     inspect: Box<InspectFullScan<K>>,
 }
 
-impl<K> From<FullScanRequestBuilder<K>> for FullScanRequest<K> {
-    fn from(builder: FullScanRequestBuilder<K>) -> Self {
+impl<K, B> From<FullScanRequestBuilder<K, B>> for FullScanRequest<K, B> {
+    fn from(builder: FullScanRequestBuilder<K, B>) -> Self {
         builder.inner
     }
 }
 
-impl<K> Default for FullScanRequest<K> {
+impl<K, B> Default for FullScanRequest<K, B> {
     fn default() -> Self {
         Self {
             chain_tip: None,
@@ -418,16 +419,16 @@ impl<K> Default for FullScanRequest<K> {
     }
 }
 
-impl<K: Ord + Clone> FullScanRequest<K> {
+impl<K: Ord + Clone, B> FullScanRequest<K, B> {
     /// Start building a [`FullScanRequest`].
-    pub fn builder() -> FullScanRequestBuilder<K> {
+    pub fn builder() -> FullScanRequestBuilder<K, B> {
         FullScanRequestBuilder {
             inner: Self::default(),
         }
     }
 
     /// Get the chain tip [`CheckPoint`] of this request (if any).
-    pub fn chain_tip(&self) -> Option<CheckPoint> {
+    pub fn chain_tip(&self) -> Option<CheckPoint<B>> {
         self.chain_tip.clone()
     }
 
@@ -459,17 +460,17 @@ impl<K: Ord + Clone> FullScanRequest<K> {
 /// See also [`FullScanRequest`].
 #[must_use]
 #[derive(Debug)]
-pub struct FullScanResult<K, A = ConfirmationBlockTime> {
+pub struct FullScanResult<K, B = BlockHash, A = ConfirmationBlockTime> {
     /// Relevant transaction data discovered during the scan.
     pub tx_update: crate::TxUpdate<A>,
     /// Last active indices for the corresponding keychains (`K`). An index is active if it had a
     /// transaction associated with the script pubkey at that index.
     pub last_active_indices: BTreeMap<K, u32>,
     /// Changes to the chain discovered during the scan.
-    pub chain_update: Option<CheckPoint>,
+    pub chain_update: Option<CheckPoint<B>>,
 }
 
-impl<K, A> Default for FullScanResult<K, A> {
+impl<K, B, A> Default for FullScanResult<K, B, A> {
     fn default() -> Self {
         Self {
             tx_update: Default::default(),
@@ -495,13 +496,13 @@ impl<'r, K: Ord + Clone> Iterator for KeychainSpkIter<'r, K> {
     }
 }
 
-struct SyncIter<'r, I, Item> {
-    request: &'r mut SyncRequest<I>,
+struct SyncIter<'r, I, B, Item> {
+    request: &'r mut SyncRequest<I, B>,
     marker: core::marker::PhantomData<Item>,
 }
 
-impl<'r, I, Item> SyncIter<'r, I, Item> {
-    fn new(request: &'r mut SyncRequest<I>) -> Self {
+impl<'r, I, B, Item> SyncIter<'r, I, B, Item> {
+    fn new(request: &'r mut SyncRequest<I, B>) -> Self {
         Self {
             request,
             marker: core::marker::PhantomData,
@@ -509,9 +510,12 @@ impl<'r, I, Item> SyncIter<'r, I, Item> {
     }
 }
 
-impl<'r, I, Item> ExactSizeIterator for SyncIter<'r, I, Item> where SyncIter<'r, I, Item>: Iterator {}
+impl<'r, I, B, Item> ExactSizeIterator for SyncIter<'r, I, B, Item> where
+    SyncIter<'r, I, B, Item>: Iterator
+{
+}
 
-impl<'r, I> Iterator for SyncIter<'r, I, ScriptBuf> {
+impl<'r, I, B> Iterator for SyncIter<'r, I, B, ScriptBuf> {
     type Item = ScriptBuf;
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -524,7 +528,7 @@ impl<'r, I> Iterator for SyncIter<'r, I, ScriptBuf> {
     }
 }
 
-impl<'r, I> Iterator for SyncIter<'r, I, Txid> {
+impl<'r, I, B> Iterator for SyncIter<'r, I, B, Txid> {
     type Item = Txid;
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -537,7 +541,7 @@ impl<'r, I> Iterator for SyncIter<'r, I, Txid> {
     }
 }
 
-impl<'r, I> Iterator for SyncIter<'r, I, OutPoint> {
+impl<'r, I, B> Iterator for SyncIter<'r, I, B, OutPoint> {
     type Item = OutPoint;
 
     fn next(&mut self) -> Option<Self::Item> {