diff --git a/impls/src/backends/lmdb.rs b/impls/src/backends/lmdb.rs
index ea11512..5dafcf6 100644
--- a/impls/src/backends/lmdb.rs
+++ b/impls/src/backends/lmdb.rs
@@ -452,6 +452,7 @@ where
 		&mut self,
 		keychain_mask: Option<&SecretKey>,
 		parent_key_id: Option<Identifier>,
+		height: Option<u64>,
 	) -> Result<Identifier, Error> {
 		let parent_key_id = parent_key_id.unwrap_or(self.parent_key_id.clone());
 		let mut deriv_idx = {
@@ -465,6 +466,12 @@ where
 		let mut return_path = self.parent_key_id.to_path();
 		return_path.depth += 1;
 		return_path.path[return_path.depth as usize - 1] = ChildNumber::from(deriv_idx);
+		if let Some(hei) = height  {
+			//u32::max is 4294967295 based on the block generating speed(1 min/block)
+			//it will take about 837 years for the height to go over the u32 range.
+			return_path.path[3] = ChildNumber::from(hei as u32); //put the height in the last index.
+
+		}
 		deriv_idx += 1;
 		let mut batch = self.batch(keychain_mask)?;
 		batch.save_child_index(&parent_key_id, deriv_idx)?;
diff --git a/libwallet/src/api_impl/owner_swap.rs b/libwallet/src/api_impl/owner_swap.rs
index 9eb2926..5316519 100644
--- a/libwallet/src/api_impl/owner_swap.rs
+++ b/libwallet/src/api_impl/owner_swap.rs
@@ -1376,7 +1376,7 @@ where
 	};
 
 	for _ in 0..secondary_key_size {
-		keys.push(wallet.next_child(keychain_mask, Some(parent_key_id.clone()))?);
+		keys.push(wallet.next_child(keychain_mask, Some(parent_key_id.clone()), None)?);
 	}
 
 	let context = (**swap_api).create_context(
diff --git a/libwallet/src/internal/keys.rs b/libwallet/src/internal/keys.rs
index 6ec7072..9883b2c 100644
--- a/libwallet/src/internal/keys.rs
+++ b/libwallet/src/internal/keys.rs
@@ -28,7 +28,7 @@ where
 	C: NodeClient + 'a,
 	K: Keychain + 'a,
 {
-	let child = wallet.next_child(keychain_mask, None)?;
+	let child = wallet.next_child(keychain_mask, None, None)?;
 	Ok(child)
 }
 
diff --git a/libwallet/src/internal/scan.rs b/libwallet/src/internal/scan.rs
index 9369fcd..daff473 100644
--- a/libwallet/src/internal/scan.rs
+++ b/libwallet/src/internal/scan.rs
@@ -21,7 +21,7 @@ use crate::mwc_core::consensus::{valid_header_version, WEEK_HEIGHT};
 use crate::mwc_core::core::HeaderVersion;
 use crate::mwc_core::global;
 use crate::mwc_core::libtx::{proof, tx_fee};
-use crate::mwc_keychain::{Identifier, Keychain, SwitchCommitmentType};
+use crate::mwc_keychain::{Identifier, Keychain, SwitchCommitmentType, ChildNumber};
 use crate::mwc_util::secp::key::SecretKey;
 use crate::mwc_util::secp::pedersen;
 use crate::mwc_util::static_secp_instance;
@@ -115,6 +115,7 @@ pub struct RestoredTxStats {
 fn identify_utxo_outputs<'a, K>(
 	keychain: &K,
 	outputs: Vec<(pedersen::Commitment, pedersen::RangeProof, bool, u64, u64)>,
+	_end_height: Option<u64>,
 ) -> Result<Vec<OutputResult>, Error>
 where
 	K: Keychain + 'a,
@@ -158,6 +159,22 @@ where
 		} else {
 			*height
 		};
+		//adding an extra check of the height.
+		//get the height used while building the key_id
+		let path = key_id.to_path();
+		let last_child_number = path.path[3];
+
+		let mut built_height = 0;
+		if let ChildNumber::Normal {index:ind} = last_child_number {
+			built_height = ind;
+		}
+		//todo compare the built_height with the height.
+		if built_height != 0 && *height <= u32::MAX as u64 {
+
+		}
+		//if the built height if too far from the height, should be reject it?
+		//if the build height or height is out of the horizon range, should we trigger the self-spend(based on the configuration)
+
 
 		debug!(
 			"Output found: {:?}, amount: {:?}, key_id: {:?}, mmr_index: {},",
@@ -217,7 +234,7 @@ where
 			let _ = s.send(StatusMessage::Scanning(show_progress, msg, perc_complete));
 		}
 
-		result_vec.append(&mut identify_utxo_outputs(keychain, outputs)?);
+		result_vec.append(&mut identify_utxo_outputs(keychain, outputs, None)?);
 
 		if highest_index <= last_retrieved_index {
 			break;
@@ -673,7 +690,7 @@ where
 		}
 
 		// Parse all node_outputs from the blocks and check ours the new ones...
-		chain_outs = identify_utxo_outputs(&keychain, node_outputs)?;
+		chain_outs = identify_utxo_outputs(&keychain, node_outputs, Some(end_height))?;
 
 		// Reporting user what outputs we found
 		if let Some(ref s) = status_send_channel {
diff --git a/libwallet/src/internal/selection.rs b/libwallet/src/internal/selection.rs
index 265e395..896d10b 100644
--- a/libwallet/src/internal/selection.rs
+++ b/libwallet/src/internal/selection.rs
@@ -528,6 +528,7 @@ where
 		fee,
 		change_outputs,
 		include_inputs_in_sum,
+		current_height,
 	)?;
 
 	Ok((parts, coins, change_amounts_derivations, fee))
@@ -655,6 +656,7 @@ pub fn inputs_and_change<'a, T: ?Sized, C, K, B>(
 	fee: u64,
 	num_change_outputs: usize,
 	include_inputs_in_sum: bool,
+	current_height: u64,
 ) -> Result<
 	(
 		Vec<Box<build::Append<K, B>>>,
@@ -710,7 +712,7 @@ where
 				part_change
 			};
 
-			let change_key = wallet.next_child(keychain_mask, None)?;
+			let change_key = wallet.next_child(keychain_mask, None, Some(current_height))?;
 
 			change_amounts_derivations.push((change_amount, change_key.clone(), None));
 			parts.push(build::output(change_amount, change_key));
diff --git a/libwallet/src/types.rs b/libwallet/src/types.rs
index 20c77ae..e9bc46b 100644
--- a/libwallet/src/types.rs
+++ b/libwallet/src/types.rs
@@ -248,6 +248,7 @@ where
 		&mut self,
 		keychain_mask: Option<&SecretKey>,
 		parent_key_id: Option<Identifier>,
+		height: Option<u64>,
 	) -> Result<Identifier, Error>;
 
 	/// last verified height of outputs directly descending from the given parent key