diff --git a/lightning-transaction-sync/tests/integration_tests.rs b/lightning-transaction-sync/tests/integration_tests.rs
index c973c3735a9..21d864bb063 100644
--- a/lightning-transaction-sync/tests/integration_tests.rs
+++ b/lightning-transaction-sync/tests/integration_tests.rs
@@ -461,7 +461,7 @@ fn test_electrum_syncs() {
 	assert!(confirmable.confirmed_txs.lock().unwrap().contains_key(&txid));
 	assert!(confirmable.unconfirmed_txs.lock().unwrap().is_empty());
 
-	// Now take a random output of the first transaction and check we'll confirm its spend.
+	// Now take an arbitrary output of the second transaction and check we'll confirm its spend.
 	let tx_res = bitcoind.client.get_transaction(&second_txid, None).unwrap();
 	let block_hash = tx_res.info.blockhash.unwrap();
 	let tx = tx_res.transaction().unwrap();
@@ -505,12 +505,14 @@ fn test_electrum_syncs() {
 	assert!(confirmable.unconfirmed_txs.lock().unwrap().is_empty());
 
 	// Check we got unconfirmed, then reconfirmed in the meantime.
+	let mut seen_txids = HashSet::new();
 	let events = std::mem::take(&mut *confirmable.events.lock().unwrap());
 	assert_eq!(events.len(), 5);
 
 	match events[0] {
 		TestConfirmableEvent::Unconfirmed(t) => {
 			assert!(t == txid || t == second_txid);
+			assert!(seen_txids.insert(t));
 		},
 		_ => panic!("Unexpected event"),
 	}
@@ -518,6 +520,7 @@ fn test_electrum_syncs() {
 	match events[1] {
 		TestConfirmableEvent::Unconfirmed(t) => {
 			assert!(t == txid || t == second_txid);
+			assert!(seen_txids.insert(t));
 		},
 		_ => panic!("Unexpected event"),
 	}
@@ -530,6 +533,7 @@ fn test_electrum_syncs() {
 	match events[3] {
 		TestConfirmableEvent::Confirmed(t, _, _) => {
 			assert!(t == txid || t == second_txid);
+			assert!(seen_txids.remove(&t));
 		},
 		_ => panic!("Unexpected event"),
 	}
@@ -537,7 +541,10 @@ fn test_electrum_syncs() {
 	match events[4] {
 		TestConfirmableEvent::Confirmed(t, _, _) => {
 			assert!(t == txid || t == second_txid);
+			assert!(seen_txids.remove(&t));
 		},
 		_ => panic!("Unexpected event"),
 	}
+
+	assert_eq!(seen_txids.len(), 0);
 }