diff --git a/tests/test_closing.py b/tests/test_closing.py
index 94c82584e..9258403d7 100644
--- a/tests/test_closing.py
+++ b/tests/test_closing.py
@@ -974,7 +974,7 @@ def test_penalty_htlc_tx_timeout(node_factory, bitcoind, chainparams):
     l2.daemon.wait_for_log('coins payment_hash: {}'.format(sticky_inv_2['payment_hash']))
 
     # l2 moves on for closed l3
-    bitcoind.generate_block(1)
+    bitcoind.generate_block(1, wait_for_mempool=1)
     l2.daemon.wait_for_log('to ONCHAIN')
     l2.daemon.wait_for_logs(['Propose handling OUR_UNILATERAL/OUR_HTLC by OUR_HTLC_TIMEOUT_TX .* after 16 blocks',
                              'Propose handling OUR_UNILATERAL/DELAYED_OUTPUT_TO_US by OUR_DELAYED_RETURN_TO_WALLET .* after 5 blocks',
@@ -983,7 +983,7 @@ def test_penalty_htlc_tx_timeout(node_factory, bitcoind, chainparams):
     l2.wait_for_onchaind_broadcast('OUR_HTLC_SUCCESS_TX',
                                    'OUR_UNILATERAL/THEIR_HTLC')
 
-    bitcoind.generate_block(1)
+    bitcoind.generate_block(1, wait_for_mempool=1)
     l2.daemon.wait_for_log('Propose handling OUR_HTLC_SUCCESS_TX/DELAYED_OUTPUT_TO_US by OUR_DELAYED_RETURN_TO_WALLET .* after 5 blocks')
 
     # after 5 blocks, l2 reclaims both their DELAYED_OUTPUT_TO_US and their delayed output
@@ -996,7 +996,7 @@ def test_penalty_htlc_tx_timeout(node_factory, bitcoind, chainparams):
     l2.wait_for_onchaind_broadcast('OUR_HTLC_TIMEOUT_TX',
                                    'OUR_UNILATERAL/OUR_HTLC')
 
-    bitcoind.generate_block(1)
+    bitcoind.generate_block(1, wait_for_mempool=1)
     l2.daemon.wait_for_log('Propose handling OUR_HTLC_TIMEOUT_TX/DELAYED_OUTPUT_TO_US by OUR_DELAYED_RETURN_TO_WALLET .* after 5 blocks')
 
     # l3 comes back up, sees cheat, penalizes l2 (revokes the htlc they've offered;
@@ -1016,7 +1016,16 @@ def test_penalty_htlc_tx_timeout(node_factory, bitcoind, chainparams):
                              'by THEIR_DELAYED_CHEAT',
                              'Resolved THEIR_REVOKED_UNILATERAL/THEIR_HTLC by THEIR_HTLC_TIMEOUT_TO_THEM',
                              'Propose handling THEIR_HTLC_TIMEOUT_TO_THEM/DELAYED_CHEAT_OUTPUT_TO_THEM by OUR_PENALTY_TX'])
-    bitcoind.generate_block(1, wait_for_mempool=2)  # OUR_PENALTY_TX + OUR_HTLC_TIMEOUT_TO_US
+
+    # Make sure we've broadcast the tx we expect (other channels shutting down can create
+    # unrelated txs!)
+
+    # In theory this could have occurred before all the previous loglines appeared.
+    l3.daemon.logsearch_start = 0
+    line = l3.daemon.wait_for_log(r'Broadcasting OUR_PENALTY_TX \([0-9a-f]*\) to resolve THEIR_HTLC_TIMEOUT_TO_THEM/DELAYED_CHEAT_OUTPUT_TO_THEM')
+    tx = re.search(r'\(([0-9a-f]*)\)', line).group(1)
+    txid = bitcoind.rpc.decoderawtransaction(tx)['txid']
+    bitcoind.generate_block(1, wait_for_mempool=[txid])
     l3.daemon.wait_for_log('Resolved THEIR_HTLC_TIMEOUT_TO_THEM/DELAYED_CHEAT_OUTPUT_TO_THEM '
                            'by our proposal OUR_PENALTY_TX')
     l2.daemon.wait_for_log('Unknown spend of OUR_HTLC_TIMEOUT_TX/DELAYED_OUTPUT_TO_US')