diff --git a/tests/test_closing.py b/tests/test_closing.py
index b2e3c9937..96d0f4075 100644
--- a/tests/test_closing.py
+++ b/tests/test_closing.py
@@ -1347,7 +1347,7 @@ def test_onchain_middleman(node_factory, bitcoind):
 
     # l2 will drop to chain.
     l2.daemon.wait_for_log('sendrawtx exit 0')
-    l1.bitcoin.generate_block(1)
+    l1.bitcoin.generate_block(1, wait_for_mempool=1)
     l2.daemon.wait_for_log(' to ONCHAIN')
     l1.daemon.wait_for_log(' to ONCHAIN')
     l2.daemon.wait_for_log('OUR_UNILATERAL/THEIR_HTLC')