diff --git a/test/functional/wallet_balance.py b/test/functional/wallet_balance.py
--- a/test/functional/wallet_balance.py
+++ b/test/functional/wallet_balance.py
@@ -312,8 +312,6 @@
         self.log.info('Put txs back into mempool of node 1 (not node 0)')
         self.nodes[0].invalidateblock(block_reorg)
         self.nodes[1].invalidateblock(block_reorg)
-        self.sync_blocks()
-        self.nodes[0].syncwithvalidationinterfacequeue()
         # wallet txs not in the mempool are untrusted
         assert_equal(self.nodes[0].getbalance(minconf=0), 0)
         self.nodes[0].generatetoaddress(1, ADDRESS_WATCHONLY)
diff --git a/test/functional/wallet_importmulti.py b/test/functional/wallet_importmulti.py
--- a/test/functional/wallet_importmulti.py
+++ b/test/functional/wallet_importmulti.py
@@ -61,6 +61,7 @@
         self.nodes[1].generate(1)
         timestamp = self.nodes[1].getblock(
             self.nodes[1].getbestblockhash())['mediantime']
+        # Sync the timestamp to the wallet, so that importmulti works
         self.nodes[1].syncwithvalidationinterfacequeue()
 
         node0_address1 = self.nodes[0].getaddressinfo(
diff --git a/test/functional/wallet_resendwallettransactions.py b/test/functional/wallet_resendwallettransactions.py
--- a/test/functional/wallet_resendwallettransactions.py
+++ b/test/functional/wallet_resendwallettransactions.py
@@ -53,6 +53,8 @@
         block.solve()
         node.submitblock(ToHex(block))
 
+        # Set correct m_best_block_time, which is used in
+        # ResendWalletTransactions
         node.syncwithvalidationinterfacequeue()
         now = int(time.time())