diff --git a/src/chainparams.h b/src/chainparams.h
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -97,6 +97,11 @@
     bool fMineBlocksOnDemand;
     CCheckpointData checkpointData;
     ChainTxData chainTxData;
+
+    // For unit tests
+    void InsertCheckpoint(int height, uint256 hash) {
+        checkpointData.mapCheckpoints.insert({height, hash});
+    }
 };
 
 /**
diff --git a/src/config.h b/src/config.h
--- a/src/config.h
+++ b/src/config.h
@@ -110,7 +110,7 @@
     void SetRPCCORSDomain(std::string corsDomain) override{};
     std::string GetRPCCORSDomain() const override { return ""; };
 
-private:
+protected:
     std::unique_ptr<CChainParams> chainParams;
 };
 
diff --git a/src/test/checkpoints_tests.cpp b/src/test/checkpoints_tests.cpp
--- a/src/test/checkpoints_tests.cpp
+++ b/src/test/checkpoints_tests.cpp
@@ -10,12 +10,15 @@
 #include "checkpoints.h"
 
 #include "chainparams.h"
+#include "config.h"
+#include "miner.h"
 #include "test/test_bitcoin.h"
 #include "uint256.h"
+#include "validation.h"
 
 #include <boost/test/unit_test.hpp>
 
-BOOST_FIXTURE_TEST_SUITE(checkpoints_tests, BasicTestingSetup)
+BOOST_FIXTURE_TEST_SUITE(checkpoints_tests, TestChain100Setup)
 
 BOOST_AUTO_TEST_CASE(sanity) {
     const auto params = CreateChainParams(CBaseChainParams::MAIN);
@@ -36,4 +39,72 @@
     BOOST_CHECK(Checkpoints::CheckBlock(checkpoints, 134444 + 1, p11111));
 }
 
+class TestChainParams : public CChainParams {
+public:
+    TestChainParams() {
+        // Copy regnet consensus params
+        auto regnetChainParams = CreateChainParams(CBaseChainParams::REGTEST);
+        consensus = regnetChainParams->GetConsensus();
+
+        // Add a checkpoint at the current chaintip
+        InsertCheckpoint(chainActive.Height(),
+                         chainActive.Tip()->GetBlockHash());
+    }
+};
+
+class TestConfig : public DummyConfig {
+public:
+    TestConfig() : DummyConfig() {
+        chainParams = std::unique_ptr<CChainParams>(new TestChainParams());
+    }
+
+    uint64_t GetMaxBlockSize() const override { return DEFAULT_MAX_BLOCK_SIZE; }
+};
+
+BOOST_AUTO_TEST_CASE(ban_fork_prior_to_checkpoint) {
+    TestConfig config;
+    CBlockIndex *genesisBlock =
+        mapBlockIndex[config.GetChainParams().GetConsensus().hashGenesisBlock];
+    assert(genesisBlock);
+
+    CBlock block;
+    block.nVersion = ComputeBlockVersion(
+        genesisBlock, config.GetChainParams().GetConsensus());
+    block.nBits = 1;
+    block.hashPrevBlock = genesisBlock->GetBlockHash();
+    block.nTime = UpdateTime(&block, config, genesisBlock);
+
+    int height = 1;
+    CMutableTransaction coinbase;
+    coinbase.vin.resize(1);
+    coinbase.vin[0].prevout = COutPoint();
+    coinbase.vin[0].scriptSig = CScript() << height << OP_0;
+    coinbase.vout.resize(1);
+    coinbase.vout[0].scriptPubKey = CScript();
+    coinbase.vout[0].nValue =
+        GetBlockSubsidy(height, config.GetChainParams().GetConsensus());
+
+    block.vtx.push_back(MakeTransactionRef(coinbase));
+    block.vtx.resize(1);
+
+    unsigned int extraNonce = 0;
+    {
+        LOCK(cs_main);
+        IncrementExtraNonce(config, &block, genesisBlock, extraNonce);
+    }
+    while (!CheckProofOfWork(block.GetHash(), block.nBits, config)) {
+        ++block.nNonce;
+    }
+
+    // Attempting to mine a new block before a checkpoint should fail
+    // Specifically, the block should not be stored to prevent out-of-memory
+    // exploits on old chains
+    std::shared_ptr<const CBlock> shared_pblock =
+        std::make_shared<const CBlock>(block);
+    bool newBlock = false;
+    BOOST_CHECK(!ProcessNewBlock(config, shared_pblock, true, &newBlock));
+    BOOST_CHECK(!newBlock);
+    BOOST_CHECK(mapBlockIndex.find(block.GetHash()) == mapBlockIndex.end());
+}
+
 BOOST_AUTO_TEST_SUITE_END()