diff --git a/test/functional/rpc_mempool_entry_fee_fields_deprecation.py b/test/functional/rpc_mempool_entry_fee_fields_deprecation.py
new file mode 100755
index 0000000000..82761ff7c8
--- /dev/null
+++ b/test/functional/rpc_mempool_entry_fee_fields_deprecation.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+# Copyright (c) 2021 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 deprecation of fee fields from top level mempool entry object"""
+
+from test_framework.blocktools import COIN
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+from test_framework.wallet import MiniWallet
+
+
+def assertions_helper(new_object, deprecated_object, deprecated_fields):
+    for field in deprecated_fields:
+        assert field in deprecated_object
+        assert field not in new_object
+
+
+class MempoolFeeFieldsDeprecationTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 2
+        self.extra_args = [[], ["-deprecatedrpc=fees"]]
+
+    def run_test(self):
+        # we get spendable outputs from the premined chain starting
+        # at block 76. see BitcoinTestFramework._initialize_chain() for details
+        self.wallet = MiniWallet(self.nodes[0])
+        self.wallet.rescan_utxos()
+
+        # we create the tx on the first node and wait until it syncs to node_deprecated
+        # thus, any differences must be coming from getmempoolentry or getrawmempool
+        tx = self.wallet.send_self_transfer(from_node=self.nodes[0])
+        self.nodes[1].sendrawtransaction(tx["hex"])
+
+        deprecated_fields = ["ancestorfees", "descendantfees", "modifiedfee", "fee"]
+        self.test_getmempoolentry(tx["txid"], deprecated_fields)
+        self.test_getrawmempool(tx["txid"], deprecated_fields)
+        self.test_deprecated_fields_match(tx["txid"])
+
+    def test_getmempoolentry(self, txid, deprecated_fields):
+
+        self.log.info("Test getmempoolentry rpc")
+        entry = self.nodes[0].getmempoolentry(txid)
+        deprecated_entry = self.nodes[1].getmempoolentry(txid)
+        assertions_helper(entry, deprecated_entry, deprecated_fields)
+
+    def test_getrawmempool(self, txid, deprecated_fields):
+
+        self.log.info("Test getrawmempool rpc")
+        entry = self.nodes[0].getrawmempool(verbose=True)[txid]
+        deprecated_entry = self.nodes[1].getrawmempool(verbose=True)[txid]
+        assertions_helper(entry, deprecated_entry, deprecated_fields)
+
+    def test_deprecated_fields_match(self, txid):
+
+        self.log.info("Test deprecated fee fields match new fees object")
+        entry = self.nodes[0].getmempoolentry(txid)
+        deprecated_entry = self.nodes[1].getmempoolentry(txid)
+
+        assert_equal(deprecated_entry["fee"], entry["fees"]["base"])
+        assert_equal(deprecated_entry["modifiedfee"], entry["fees"]["modified"])
+        assert_equal(deprecated_entry["descendantfees"], entry["fees"]["descendant"] * COIN)
+        assert_equal(deprecated_entry["ancestorfees"], entry["fees"]["ancestor"] * COIN)
+
+
+if __name__ == "__main__":
+    MempoolFeeFieldsDeprecationTest().main()
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 916cd94b79..2fc5d2c56e 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -309,6 +309,7 @@ BASE_SCRIPTS = [
     'feature_presegwit_node_upgrade.py',
     'feature_settings.py',
     'rpc_getdescriptorinfo.py',
+    'rpc_mempool_entry_fee_fields_deprecation.py',
     'rpc_help.py',
     'feature_help.py',
     'feature_shutdown.py',