diff --git a/rai/core_test/block_store.cpp b/rai/core_test/block_store.cpp
index dac1f4be..7b8ba037 100644
--- a/rai/core_test/block_store.cpp
+++ b/rai/core_test/block_store.cpp
@@ -525,4 +525,19 @@ TEST (block_store, frontier)
 	ASSERT_EQ (account, store.frontier_get (transaction, hash));
 	store.frontier_del (transaction, hash);
 	ASSERT_TRUE (store.frontier_get (transaction, hash).is_zero ());
+}
+
+TEST (block_store, block_replace)
+{
+    bool init (false);
+    rai::block_store store (init, rai::unique_path ());
+	ASSERT_TRUE (!init);
+	rai::send_block send1 (0, 0, 0, 0, 0, 1);
+	rai::send_block send2 (0, 0, 0, 0, 0, 2);
+	rai::transaction transaction (store.environment, nullptr, true);
+	store.block_put (transaction, 0, send1);
+	store.block_put (transaction, 0, send2);
+	auto block3 (store.block_get (transaction, 0));
+	ASSERT_NE (nullptr, block3);
+	ASSERT_EQ (2, block3->block_work ());
 }
\ No newline at end of file
diff --git a/rai/core_test/node.cpp b/rai/core_test/node.cpp
index a6e5a7ab..6ecbcfa0 100644
--- a/rai/core_test/node.cpp
+++ b/rai/core_test/node.cpp
@@ -401,4 +401,40 @@ TEST (node_config, random_rep)
 	rai::node_config config1 (100, logging1);
 	auto rep (config1.random_representative ());
 	ASSERT_NE (config1.preconfigured_representatives.end (), std::find (config1.preconfigured_representatives.begin (), config1.preconfigured_representatives.end (), rep));
+}
+
+TEST (node, block_replace)
+{
+	rai::system system (24000, 2);
+	system.wallet (0)->insert (rai::test_genesis_key.prv);
+    ASSERT_FALSE (system.wallet (0)->send_sync (rai::test_genesis_key.pub, 0, 1000));
+	std::unique_ptr <rai::block> block1;
+	{
+		rai::transaction transaction (system.nodes [0]->store.environment, nullptr, false);
+		block1 = system.nodes [0]->store.block_get (transaction, system.nodes [0]->ledger.latest (transaction, rai::test_genesis_key.pub));
+	}
+	ASSERT_NE (nullptr, block1);
+	auto initial_work (block1->block_work ());
+	while (rai::work_value (block1->root (), block1->block_work ()) <= rai::work_value (block1->root (), initial_work))
+	{
+		system.work.generate (*block1);
+	}
+	system.nodes [1]->network.republish_block (block1->clone (), 0);
+	auto iterations1 (0);
+	std::unique_ptr <rai::block> block2;
+	while (block2 == nullptr)
+	{
+		system.poll ();
+		++iterations1;
+		ASSERT_LT (iterations1, 200);
+		rai::transaction transaction (system.nodes [0]->store.environment, nullptr, false);
+		auto block (system.nodes [0]->store.block_get (transaction, system.nodes [0]->ledger.latest (transaction, rai::test_genesis_key.pub)));
+		if (block->block_work () != initial_work)
+		{
+			block2 = std::move (block);
+		}
+	}
+	ASSERT_NE (initial_work, block1->block_work ());
+	ASSERT_EQ (block1->block_work (), block2->block_work ());
+	ASSERT_GT (rai::work_value (block2->root (), block2->block_work ()), rai::work_value (block1->root (), initial_work));
 }
\ No newline at end of file
diff --git a/rai/node.cpp b/rai/node.cpp
index 07ae04e2..75f9cc11 100644
--- a/rai/node.cpp
+++ b/rai/node.cpp
@@ -2309,6 +2309,24 @@ rai::process_return rai::node::process_receive (rai::block const & block_a)
         }
         case rai::process_result::old:
         {
+			{
+				auto root (block_a.root ());
+				auto hash (block_a.hash ());
+				rai::transaction transaction (store.environment, nullptr, true);
+				auto existing (store.block_get (transaction, hash));
+				if (existing != nullptr)
+				{
+					// Replace block with one that has higher work value
+					if (rai::work_value (root, block_a.block_work ()) > rai::work_value (root, existing->block_work ()))
+					{
+						store.block_put (transaction, hash, block_a);
+					}
+				}
+				else
+				{
+					// Could have been rolled back, maybe
+				}
+			}
             if (config.logging.ledger_duplicate_logging ())
             {
                 BOOST_LOG (log) << boost::str (boost::format ("Old for: %1%") % block_a.hash ().to_string ());
diff --git a/rai/secure.cpp b/rai/secure.cpp
index d8c84be3..ceb26b53 100644
--- a/rai/secure.cpp
+++ b/rai/secure.cpp
@@ -564,7 +564,7 @@ void rai::serialize_block (rai::stream & stream_a, rai::block const & block_a)
     block_a.serialize (stream_a);
 }
 
-bool rai::work_validate (rai::block_hash const & root_a, uint64_t work_a)
+uint64_t rai::work_value (rai::block_hash const & root_a, uint64_t work_a)
 {
     uint64_t result;
     blake2b_state hash;
@@ -572,7 +572,13 @@ bool rai::work_validate (rai::block_hash const & root_a, uint64_t work_a)
     blake2b_update (&hash, reinterpret_cast <uint8_t *> (&work_a), sizeof (work_a));
     blake2b_update (&hash, root_a.bytes.data (), root_a.bytes.size ());
     blake2b_final (&hash, reinterpret_cast <uint8_t *> (&result), sizeof (result));
-    return result < rai::block::publish_threshold;
+	return result;
+}
+
+bool rai::work_validate (rai::block_hash const & root_a, uint64_t work_a)
+{
+    auto result (rai::work_value (root_a, work_a) < rai::block::publish_threshold);
+	return result;
 }
 
 bool rai::work_validate (rai::block & block_a)
diff --git a/rai/secure.hpp b/rai/secure.hpp
index 49f06f76..5d872d90 100644
--- a/rai/secure.hpp
+++ b/rai/secure.hpp
@@ -96,6 +96,7 @@ std::unique_ptr <rai::block> deserialize_block (rai::stream &);
 std::unique_ptr <rai::block> deserialize_block (rai::stream &, rai::block_type);
 std::unique_ptr <rai::block> deserialize_block_json (boost::property_tree::ptree const &);
 void serialize_block (rai::stream &, rai::block const &);
+uint64_t work_value (rai::block_hash const &, uint64_t);
 bool work_validate (rai::block &);
 bool work_validate (rai::block_hash const &, uint64_t);
 class send_hashables