diff --git a/test/functional/zapwallettxes.py b/test/functional/zapwallettxes.py
index 544399d4c..159d12ada 100755
--- a/test/functional/zapwallettxes.py
+++ b/test/functional/zapwallettxes.py
@@ -1,77 +1,82 @@
 #!/usr/bin/env python3
 # Copyright (c) 2014-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test the zapwallettxes functionality.
 
 - start two bitcoind nodes
 - create two transactions on node 0 - one is confirmed and one is unconfirmed.
 - restart node 0 and verify that both the confirmed and the unconfirmed
   transactions are still available.
 - restart node 0 with zapwallettxes and persistmempool, and verify that both
   the confirmed and the unconfirmed transactions are still available.
 - restart node 0 with just zapwallettxed and verify that the confirmed
   transactions are still available, but that the unconfirmed transaction has
   been zapped.
 """
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import (assert_equal,
-                                 assert_raises_rpc_error,
-                                 )
+from test_framework.util import (
+    assert_equal,
+    assert_raises_rpc_error,
+    wait_until,
+)
 
 
 class ZapWalletTXesTest (BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 2
 
     def run_test(self):
         self.log.info("Mining blocks...")
         self.nodes[0].generate(1)
         self.sync_all()
         self.nodes[1].generate(100)
         self.sync_all()
 
         # This transaction will be confirmed
         txid1 = self.nodes[0].sendtoaddress(self.nodes[1].getnewaddress(), 10)
 
         self.nodes[0].generate(1)
         self.sync_all()
 
         # This transaction will not be confirmed
         txid2 = self.nodes[0].sendtoaddress(self.nodes[1].getnewaddress(), 20)
 
         # Confirmed and unconfirmed transactions are now in the wallet.
         assert_equal(self.nodes[0].gettransaction(txid1)['txid'], txid1)
         assert_equal(self.nodes[0].gettransaction(txid2)['txid'], txid2)
 
         # Stop-start node0. Both confirmed and unconfirmed transactions remain in the wallet.
         self.stop_node(0)
         self.start_node(0)
 
         assert_equal(self.nodes[0].gettransaction(txid1)['txid'], txid1)
         assert_equal(self.nodes[0].gettransaction(txid2)['txid'], txid2)
 
         # Stop node0 and restart with zapwallettxes and persistmempool. The unconfirmed
         # transaction is zapped from the wallet, but is re-added when the mempool is reloaded.
         self.stop_node(0)
         self.start_node(0, ["-persistmempool=1", "-zapwallettxes=2"])
 
+        wait_until(lambda: self.nodes[0].getmempoolinfo()[
+                   'size'] == 1, timeout=3)
+
         assert_equal(self.nodes[0].gettransaction(txid1)['txid'], txid1)
         assert_equal(self.nodes[0].gettransaction(txid2)['txid'], txid2)
 
         # Stop node0 and restart with zapwallettxes, but not persistmempool.
         # The unconfirmed transaction is zapped and is no longer in the wallet.
         self.stop_node(0)
         self.start_node(0, ["-zapwallettxes=2"])
 
         # tx1 is still be available because it was confirmed
         assert_equal(self.nodes[0].gettransaction(txid1)['txid'], txid1)
 
         # This will raise an exception because the unconfirmed transaction has been zapped
         assert_raises_rpc_error(-5, 'Invalid or non-wallet transaction id',
                                 self.nodes[0].gettransaction, txid2)
 
 
 if __name__ == '__main__':
     ZapWalletTXesTest().main()