diff --git a/lightning-transaction-sync/src/common.rs b/lightning-transaction-sync/src/common.rs
index 88e52de186d..02df6c28b4d 100644
--- a/lightning-transaction-sync/src/common.rs
+++ b/lightning-transaction-sync/src/common.rs
@@ -133,6 +133,10 @@ impl FilterQueue {
 	}
 }
 
+pub(crate) fn is_potentially_unsafe_merkle_leaf(tx: &Transaction) -> bool {
+	tx.base_size() == 64
+}
+
 #[derive(Debug)]
 pub(crate) struct ConfirmedTx {
 	pub tx: Transaction,
@@ -141,3 +145,35 @@ pub(crate) struct ConfirmedTx {
 	pub block_height: u32,
 	pub pos: usize,
 }
+
+#[cfg(test)]
+mod tests {
+	use super::is_potentially_unsafe_merkle_leaf;
+
+	use bitcoin::absolute::LockTime;
+	use bitcoin::hashes::Hash;
+	use bitcoin::transaction::Version;
+	use bitcoin::{Amount, OutPoint, ScriptBuf, Sequence, Transaction, TxIn, TxOut, Txid, Witness};
+
+	#[test]
+	fn merkle_leaf_check_uses_non_witness_size() {
+		let mut witness = Witness::new();
+		witness.push(vec![0]);
+
+		let tx = Transaction {
+			version: Version::TWO,
+			lock_time: LockTime::ZERO,
+			input: vec![TxIn {
+				previous_output: OutPoint { txid: Txid::all_zeros(), vout: 0 },
+				script_sig: ScriptBuf::new(),
+				sequence: Sequence::ZERO,
+				witness,
+			}],
+			output: vec![TxOut { value: Amount::ZERO, script_pubkey: ScriptBuf::from(vec![0; 4]) }],
+		};
+
+		assert_eq!(tx.base_size(), 64, "test setup: base size must be 64");
+		assert!(tx.total_size() > 64, "test setup: witness must pad total size");
+		assert!(is_potentially_unsafe_merkle_leaf(&tx));
+	}
+}
diff --git a/lightning-transaction-sync/src/electrum.rs b/lightning-transaction-sync/src/electrum.rs
index cb937248f41..2eb146809a6 100644
--- a/lightning-transaction-sync/src/electrum.rs
+++ b/lightning-transaction-sync/src/electrum.rs
@@ -5,7 +5,7 @@
 // http://opensource.org/licenses/MIT>, at your option. You may not use this file except in
 // accordance with one or both of these licenses.
 
-use crate::common::{ConfirmedTx, FilterQueue, SyncState};
+use crate::common::{is_potentially_unsafe_merkle_leaf, ConfirmedTx, FilterQueue, SyncState};
 use crate::error::{InternalError, TxSyncError};
 
 use electrum_client::utils::validate_merkle_proof;
@@ -277,6 +277,11 @@ impl<L: Logger> ElectrumSyncClient<L> {
 		for txid in &sync_state.watched_transactions {
 			match self.client.transaction_get(&txid) {
 				Ok(tx) => {
+					if tx.compute_txid() != *txid {
+						log_error!(self.logger, "Retrieved transaction for txid {} doesn't match expectations. This should not happen. Please verify server integrity.", txid);
+						return Err(InternalError::Failed);
+					}
+
 					// Bitcoin Core's Merkle tree implementation has no way to discern between
 					// internal and leaf node entries. As a consequence it is susceptible to an
 					// attacker injecting additional transactions by crafting 64-byte
@@ -284,7 +289,7 @@ impl<L: Logger> ElectrumSyncClient<L> {
 					// https://web.archive.org/web/20240329003521/https://bitslog.com/2018/06/09/leaf-node-weakness-in-bitcoin-merkle-tree-design/).
 					// To protect against this (highly unlikely) attack vector, we check that the
 					// transaction is at least 65 bytes in length.
-					if tx.total_size() == 64 {
+					if is_potentially_unsafe_merkle_leaf(&tx) {
 						log_error!(self.logger, "Skipping transaction {} due to retrieving potentially invalid tx data.", txid);
 						continue;
 					}
@@ -369,6 +374,11 @@ impl<L: Logger> ElectrumSyncClient<L> {
 
 						match self.client.transaction_get(&txid) {
 							Ok(tx) => {
+								if tx.compute_txid() != txid {
+									log_error!(self.logger, "Retrieved transaction for txid {} doesn't match expectations. This should not happen. Please verify server integrity.", txid);
+									return Err(InternalError::Failed);
+								}
+
 								let mut is_spend = false;
 								for txin in &tx.input {
 									let watched_outpoint =
@@ -517,3 +527,23 @@ impl<L: Logger> Filter for ElectrumSyncClient<L> {
 		locked_queue.outputs.insert(output.outpoint.into_bitcoin_outpoint(), output);
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	#[test]
+	fn transaction_get_responses_are_verified_at_call_sites() {
+		let src = include_str!("electrum.rs");
+		let watched_transaction_check = concat!("if tx.compute_", "txid() != *txid");
+		let watched_output_spend_check = concat!("if tx.compute_", "txid() != txid");
+
+		assert!(
+			src.contains(watched_transaction_check),
+			"watched transaction_get responses must be verified against the requested txid"
+		);
+		assert!(
+			src.contains(watched_output_spend_check),
+			"watched-output spend transaction_get responses must be verified against the \
+			 requested txid"
+		);
+	}
+}
diff --git a/lightning-transaction-sync/src/esplora.rs b/lightning-transaction-sync/src/esplora.rs
index 52cfb394464..07d2ba26219 100644
--- a/lightning-transaction-sync/src/esplora.rs
+++ b/lightning-transaction-sync/src/esplora.rs
@@ -5,7 +5,7 @@
 // http://opensource.org/licenses/MIT>, at your option. You may not use this file except in
 // accordance with one or both of these licenses.
 
-use crate::common::{ConfirmedTx, FilterQueue, SyncState};
+use crate::common::{is_potentially_unsafe_merkle_leaf, ConfirmedTx, FilterQueue, SyncState};
 use crate::error::{InternalError, TxSyncError};
 
 use lightning::chain::WatchedOutput;
@@ -393,7 +393,7 @@ impl<L: Logger> EsploraSyncClient<L> {
 				// https://web.archive.org/web/20240329003521/https://bitslog.com/2018/06/09/leaf-node-weakness-in-bitcoin-merkle-tree-design/).
 				// To protect against this (highly unlikely) attack vector, we check that the
 				// transaction is at least 65 bytes in length.
-				if tx.total_size() == 64 {
+				if is_potentially_unsafe_merkle_leaf(&tx) {
 					log_error!(
 						self.logger,
 						"Skipping transaction {} due to retrieving potentially invalid tx data.",