diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index 6ed7350ea2..5aae2cccd0 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -23,7 +23,17 @@
 
 #include <boost/test/unit_test.hpp>
 
-BOOST_FIXTURE_TEST_SUITE(miner_tests, TestingSetup)
+namespace miner_tests {
+struct MinerTestingSetup : public TestingSetup {
+    void TestPackageSelection(const CChainParams& chainparams, const CScript& scriptPubKey, const std::vector<CTransactionRef>& txFirst) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_node.mempool->cs);
+    bool TestSequenceLocks(const CTransaction& tx, int flags) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_node.mempool->cs)
+    {
+        return CheckSequenceLocks(*m_node.mempool, tx, flags);
+    }
+};
+} // namespace miner_tests
+
+BOOST_FIXTURE_TEST_SUITE(miner_tests, MinerTestingSetup)
 
 // BOOST_CHECK_EXCEPTION predicates to check the specific validation error
 class HasReason {
@@ -89,16 +99,10 @@ static CBlockIndex CreateBlockIndex(int nHeight) EXCLUSIVE_LOCKS_REQUIRED(cs_mai
     return index;
 }
 
-static bool TestSequenceLocks(const CTransaction &tx, int flags) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
-{
-    LOCK(::mempool.cs);
-    return CheckSequenceLocks(::mempool, tx, flags);
-}
-
 // Test suite for ancestor feerate transaction selection.
 // Implemented as an additional function, rather than a separate test case,
 // to allow reusing the blockchain created in CreateNewBlock_validity.
-static void TestPackageSelection(const CChainParams& chainparams, const CScript& scriptPubKey, const std::vector<CTransactionRef>& txFirst) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs)
+void MinerTestingSetup::TestPackageSelection(const CChainParams& chainparams, const CScript& scriptPubKey, const std::vector<CTransactionRef>& txFirst)
 {
     // Test the ancestor feerate transaction selection.
     TestMemPoolEntryHelper entry;
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index a5bc15bb9f..49aa344b33 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -17,16 +17,6 @@ bool CheckInputs(const CTransaction& tx, TxValidationState &state, const CCoinsV
 
 BOOST_AUTO_TEST_SUITE(tx_validationcache_tests)
 
-static bool
-ToMemPool(const CMutableTransaction& tx)
-{
-    LOCK(cs_main);
-
-    TxValidationState state;
-    return AcceptToMemoryPool(mempool, state, MakeTransactionRef(tx),
-                              nullptr /* plTxnReplaced */, true /* bypass_limits */, 0 /* nAbsurdFee */);
-}
-
 BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup)
 {
     // Make sure skipping validation of transactions that were
@@ -35,6 +25,14 @@ BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup)
 
     CScript scriptPubKey = CScript() <<  ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
 
+    const auto ToMemPool = [this](const CMutableTransaction& tx) {
+        LOCK(cs_main);
+
+        TxValidationState state;
+        return AcceptToMemoryPool(*m_node.mempool, state, MakeTransactionRef(tx),
+            nullptr /* plTxnReplaced */, true /* bypass_limits */, 0 /* nAbsurdFee */);
+    };
+
     // Create a double-spend of mature coinbase txn:
     std::vector<CMutableTransaction> spends;
     spends.resize(2);