diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 6bf41d7ba8..e3cf7f3717 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -458,16 +458,16 @@ static RPCHelpMan getdifficulty()
 
 static std::vector<RPCResult> MempoolEntryDescription() { return {
     RPCResult{RPCResult::Type::NUM, "vsize", "virtual transaction size. This can be different from actual serialized size for high-sigop transactions."},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "fee", "transaction fee in " + CURRENCY_UNIT + " (DEPRECATED)"},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "modifiedfee", "transaction fee with fee deltas used for mining priority (DEPRECATED)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "fee", /*optional=*/true, "transaction fee in " + CURRENCY_UNIT + " (DEPRECATED)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "modifiedfee", /*optional=*/true, "transaction fee with fee deltas used for mining priority (DEPRECATED)"},
     RPCResult{RPCResult::Type::NUM_TIME, "time", "local time transaction entered pool in " + UNIX_EPOCH_TIME},
     RPCResult{RPCResult::Type::NUM, "height", "block height when transaction entered pool"},
     RPCResult{RPCResult::Type::NUM, "descendantcount", "number of in-mempool descendant transactions (including this one)"},
     RPCResult{RPCResult::Type::NUM, "descendantsize", "size of in-mempool descendants (including this one)"},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "descendantfees", "modified fees (see above) of in-mempool descendants (including this one) (DEPRECATED)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "descendantfees",  /*optional=*/true, "modified fees (see above) of in-mempool descendants (including this one) (DEPRECATED)"},
     RPCResult{RPCResult::Type::NUM, "ancestorcount", "number of in-mempool ancestor transactions (including this one)"},
     RPCResult{RPCResult::Type::NUM, "ancestorsize", "size of in-mempool ancestors (including this one)"},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "ancestorfees", "modified fees (see above) of in-mempool ancestors (including this one) (DEPRECATED)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "ancestorfees", /*optional=*/true, "modified fees (see above) of in-mempool ancestors (including this one) (DEPRECATED)"},
     RPCResult{RPCResult::Type::OBJ, "fees", "",
     {
         RPCResult{RPCResult::Type::STR_AMOUNT, "base", "transaction fee in " + CURRENCY_UNIT},
diff --git a/src/validation.cpp b/src/validation.cpp
index c0a8167219..2219768b58 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -825,8 +825,8 @@ bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws, P
     // transactions into the mempool can be exploited as a DoS attack.
     unsigned int currentBlockScriptVerifyFlags = GetBlockScriptFlags(m_active_chainstate.m_chain.Tip(), chainparams.GetConsensus());
     if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags, txdata, m_active_chainstate.CoinsTip())) {
-        return error("%s: BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s",
-                __func__, hash.ToString(), state.ToString());
+        LogPrintf("BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s\n", hash.ToString(), state.ToString());
+        return Assume(false);
     }
 
     return true;
diff --git a/test/functional/mempool_persist.py b/test/functional/mempool_persist.py
index a40c7f4e72..bc9a6d949c 100755
--- a/test/functional/mempool_persist.py
+++ b/test/functional/mempool_persist.py
@@ -154,7 +154,7 @@ class MempoolPersistTest(BitcoinTestFramework):
         self.log.debug("Stop nodes, make node1 use mempool.dat from node0. Verify it has 6 transactions")
         os.rename(mempooldat0, mempooldat1)
         self.stop_nodes()
-        self.start_node(1, extra_args=[])
+        self.start_node(1, extra_args=["-persistmempool"])
         assert self.nodes[1].getmempoolinfo()["loaded"]
         assert_equal(len(self.nodes[1].getrawmempool()), 6)