diff --git a/rai/core_test/block_store.cpp b/rai/core_test/block_store.cpp
index 93b3a71b..4622d2dc 100644
--- a/rai/core_test/block_store.cpp
+++ b/rai/core_test/block_store.cpp
@@ -240,7 +240,7 @@ TEST (bootstrap, simple)
 	auto block3 (store.unchecked_get (transaction, block1->previous ()));
 	ASSERT_FALSE (block3.empty ());
 	ASSERT_EQ (*block1, *block3[0]);
-	store.unchecked_del (transaction, block1->previous (), block1);
+	store.unchecked_del (transaction, rai::unchecked_key (block1->previous (), block1->hash ()));
 	auto block4 (store.unchecked_get (transaction, block1->previous ()));
 	ASSERT_TRUE (block4.empty ());
 }
@@ -391,9 +391,9 @@ TEST (block_store, one_bootstrap)
 	auto begin (store.unchecked_begin (transaction));
 	auto end (store.unchecked_end ());
 	ASSERT_NE (end, begin);
-	rai::uint256_union hash1 (begin->first);
+	rai::uint256_union hash1 (begin->first.key ());
 	ASSERT_EQ (block1->hash (), hash1);
-	auto blocks (store.unchecked_get (transaction, rai::block_hash (begin->first)));
+	auto blocks (store.unchecked_get (transaction, hash1));
 	ASSERT_EQ (1, blocks.size ());
 	auto block2 (blocks[0]);
 	ASSERT_EQ (*block1, *block2);
@@ -877,7 +877,7 @@ TEST (block_store, upgrade_v6_v7)
 }
 
 // Databases need to be dropped in order to convert to dupsort compatible
-TEST (block_store, change_dupsort)
+TEST (block_store, DISABLED_change_dupsort) // Unchecked is no longer dupsort table
 {
 	auto path (rai::unique_path ());
 	bool init (false);
diff --git a/rai/node/lmdb.cpp b/rai/node/lmdb.cpp
index 4e1f576e..64f632e6 100644
--- a/rai/node/lmdb.cpp
+++ b/rai/node/lmdb.cpp
@@ -688,21 +688,21 @@ rai::store_iterator<rai::account, rai::uint128_union> rai::mdb_store::representa
 	return result;
 }
 
-rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> rai::mdb_store::unchecked_begin (rai::transaction const & transaction_a)
+rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> rai::mdb_store::unchecked_begin (rai::transaction const & transaction_a)
 {
-	rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> result (std::make_unique<rai::mdb_iterator<rai::account, std::shared_ptr<rai::block>>> (transaction_a, unchecked));
+	rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> result (std::make_unique<rai::mdb_iterator<rai::unchecked_key, std::shared_ptr<rai::block>>> (transaction_a, unchecked));
 	return result;
 }
 
-rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> rai::mdb_store::unchecked_begin (rai::transaction const & transaction_a, rai::block_hash const & hash_a)
+rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> rai::mdb_store::unchecked_begin (rai::transaction const & transaction_a, rai::unchecked_key const & key_a)
 {
-	rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> result (std::make_unique<rai::mdb_iterator<rai::block_hash, std::shared_ptr<rai::block>>> (transaction_a, unchecked, rai::mdb_val (hash_a)));
+	rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> result (std::make_unique<rai::mdb_iterator<rai::unchecked_key, std::shared_ptr<rai::block>>> (transaction_a, unchecked, rai::mdb_val (key_a)));
 	return result;
 }
 
-rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> rai::mdb_store::unchecked_end ()
+rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> rai::mdb_store::unchecked_end ()
 {
-	rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> result (nullptr);
+	rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> result (nullptr);
 	return result;
 }
 
@@ -752,7 +752,7 @@ meta (0)
 		error_a |= mdb_dbi_open (env.tx (transaction), "pending_v1", MDB_CREATE, &pending_v1) != 0;
 		error_a |= mdb_dbi_open (env.tx (transaction), "blocks_info", MDB_CREATE, &blocks_info) != 0;
 		error_a |= mdb_dbi_open (env.tx (transaction), "representation", MDB_CREATE, &representation) != 0;
-		error_a |= mdb_dbi_open (env.tx (transaction), "unchecked", MDB_CREATE | MDB_DUPSORT, &unchecked) != 0;
+		error_a |= mdb_dbi_open (env.tx (transaction), "unchecked", MDB_CREATE, &unchecked) != 0;
 		error_a |= mdb_dbi_open (env.tx (transaction), "checksum", MDB_CREATE, &checksum) != 0;
 		error_a |= mdb_dbi_open (env.tx (transaction), "vote", MDB_CREATE, &vote) != 0;
 		error_a |= mdb_dbi_open (env.tx (transaction), "meta", MDB_CREATE, &meta) != 0;
@@ -867,6 +867,8 @@ void rai::mdb_store::do_upgrades (rai::transaction const & transaction_a)
 		case 10:
 			upgrade_v10_to_v11 (transaction_a);
 		case 11:
+			upgrade_v11_to_v12 (transaction_a);
+		case 12:
 			break;
 		default:
 			assert (false);
@@ -1068,6 +1070,13 @@ void rai::mdb_store::upgrade_v10_to_v11 (rai::transaction const & transaction_a)
 	mdb_drop (env.tx (transaction_a), unsynced, 1);
 }
 
+void rai::mdb_store::upgrade_v11_to_v12 (rai::transaction const & transaction_a)
+{
+	version_put (transaction_a, 12);
+	mdb_drop (env.tx (transaction_a), unchecked, 1);
+	mdb_dbi_open (env.tx (transaction_a), "unchecked", MDB_CREATE, &unchecked);
+}
+
 void rai::mdb_store::clear (MDB_dbi db_a)
 {
 	auto transaction (tx_begin_write ());
@@ -1731,26 +1740,17 @@ void rai::mdb_store::unchecked_clear (rai::transaction const & transaction_a)
 	release_assert (status == 0);
 }
 
+void rai::mdb_store::unchecked_put (rai::transaction const & transaction_a, rai::unchecked_key const & key_a, std::shared_ptr<rai::block> const & block_a)
+{
+	mdb_val block (block_a);
+	auto status (mdb_put (env.tx (transaction_a), unchecked, rai::mdb_val (key_a), block, 0));
+	release_assert (status == 0);
+}
+
 void rai::mdb_store::unchecked_put (rai::transaction const & transaction_a, rai::block_hash const & hash_a, std::shared_ptr<rai::block> const & block_a)
 {
-	// Checking if same unchecked block is already in database
-	bool exists (false);
-	auto block_hash (block_a->hash ());
-	auto cached (unchecked_get (transaction_a, hash_a));
-	for (auto i (cached.begin ()), n (cached.end ()); i != n && !exists; ++i)
-	{
-		if ((*i)->hash () == block_hash)
-		{
-			exists = true;
-		}
-	}
-	// Inserting block if it wasn't found in database
-	if (!exists)
-	{
-		mdb_val block (block_a);
-		auto status (mdb_put (env.tx (transaction_a), unchecked, rai::mdb_val (hash_a), block, 0));
-		release_assert (status == 0);
-	}
+	rai::unchecked_key key (hash_a, block_a->hash ());
+	unchecked_put (transaction_a, key, block_a);
 }
 
 std::shared_ptr<rai::vote> rai::mdb_store::vote_get (rai::transaction const & transaction_a, rai::account const & account_a)
@@ -1770,7 +1770,7 @@ std::shared_ptr<rai::vote> rai::mdb_store::vote_get (rai::transaction const & tr
 std::vector<std::shared_ptr<rai::block>> rai::mdb_store::unchecked_get (rai::transaction const & transaction_a, rai::block_hash const & hash_a)
 {
 	std::vector<std::shared_ptr<rai::block>> result;
-	for (auto i (unchecked_begin (transaction_a, hash_a)), n (unchecked_end ()); i != n && rai::block_hash (i->first) == hash_a; ++i)
+	for (auto i (unchecked_begin (transaction_a, rai::unchecked_key (hash_a, 0))), n (unchecked_end ()); i != n && rai::block_hash (i->first.key ()) == hash_a; ++i)
 	{
 		std::shared_ptr<rai::block> block (i->second);
 		result.push_back (block);
@@ -1778,10 +1778,15 @@ std::vector<std::shared_ptr<rai::block>> rai::mdb_store::unchecked_get (rai::tra
 	return result;
 }
 
-void rai::mdb_store::unchecked_del (rai::transaction const & transaction_a, rai::block_hash const & hash_a, std::shared_ptr<rai::block> block_a)
+bool rai::mdb_store::unchecked_exists (rai::transaction const & transaction_a, rai::unchecked_key const & key_a)
 {
-	rai::mdb_val block (block_a);
-	auto status (mdb_del (env.tx (transaction_a), unchecked, rai::mdb_val (hash_a), block));
+	auto iterator (unchecked_begin (transaction_a, key_a));
+	return iterator != unchecked_end () && rai::unchecked_key (iterator->first) == key_a;
+}
+
+void rai::mdb_store::unchecked_del (rai::transaction const & transaction_a, rai::unchecked_key const & key_a)
+{
+	auto status (mdb_del (env.tx (transaction_a), unchecked, rai::mdb_val (key_a), nullptr));
 	release_assert (status == 0 || status == MDB_NOTFOUND);
 }
 
diff --git a/rai/node/lmdb.hpp b/rai/node/lmdb.hpp
index fe9ce365..93b7a25b 100644
--- a/rai/node/lmdb.hpp
+++ b/rai/node/lmdb.hpp
@@ -212,12 +212,14 @@ public:
 	rai::store_iterator<rai::account, rai::uint128_union> representation_end () override;
 
 	void unchecked_clear (rai::transaction const &) override;
+	void unchecked_put (rai::transaction const &, rai::unchecked_key const &, std::shared_ptr<rai::block> const &) override;
 	void unchecked_put (rai::transaction const &, rai::block_hash const &, std::shared_ptr<rai::block> const &) override;
 	std::vector<std::shared_ptr<rai::block>> unchecked_get (rai::transaction const &, rai::block_hash const &) override;
-	void unchecked_del (rai::transaction const &, rai::block_hash const &, std::shared_ptr<rai::block>) override;
-	rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &) override;
-	rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &, rai::block_hash const &) override;
-	rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> unchecked_end () override;
+	bool unchecked_exists (rai::transaction const &, rai::unchecked_key const &) override;
+	void unchecked_del (rai::transaction const &, rai::unchecked_key const &) override;
+	rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &) override;
+	rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &, rai::unchecked_key const &) override;
+	rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> unchecked_end () override;
 	size_t unchecked_count (rai::transaction const &) override;
 
 	void checksum_put (rai::transaction const &, uint64_t, uint8_t, rai::checksum const &) override;
diff --git a/rai/node/node.cpp b/rai/node/node.cpp
index 1ffd2897..97bd15f4 100644
--- a/rai/node/node.cpp
+++ b/rai/node/node.cpp
@@ -1585,7 +1585,7 @@ void rai::block_processor::queue_unchecked (rai::transaction const & transaction
 	auto cached (node.store.unchecked_get (transaction_a, hash_a));
 	for (auto i (cached.begin ()), n (cached.end ()); i != n; ++i)
 	{
-		node.store.unchecked_del (transaction_a, hash_a, *i);
+		node.store.unchecked_del (transaction_a, rai::unchecked_key (hash_a, (*i)->hash ()));
 		add (*i, std::chrono::steady_clock::time_point ());
 	}
 	std::lock_guard<std::mutex> lock (node.gap_cache.mutex);
diff --git a/rai/node/rpc.cpp b/rai/node/rpc.cpp
index 099e4af2..0832248e 100644
--- a/rai/node/rpc.cpp
+++ b/rai/node/rpc.cpp
@@ -3036,13 +3036,13 @@ void rai::rpc_handler::unchecked_keys ()
 	{
 		boost::property_tree::ptree unchecked;
 		auto transaction (node.store.tx_begin_read ());
-		for (auto i (node.store.unchecked_begin (transaction, key)), n (node.store.unchecked_end ()); i != n && unchecked.size () < count; ++i)
+		for (auto i (node.store.unchecked_begin (transaction, rai::unchecked_key (key, 0))), n (node.store.unchecked_end ()); i != n && unchecked.size () < count; ++i)
 		{
 			boost::property_tree::ptree entry;
 			auto block (i->second);
 			std::string contents;
 			block->serialize_json (contents);
-			entry.put ("key", rai::block_hash (i->first).to_string ());
+			entry.put ("key", rai::block_hash (i->first.key ()).to_string ());
 			entry.put ("hash", block->hash ().to_string ());
 			entry.put ("contents", contents);
 			unchecked.push_back (std::make_pair ("", entry));
diff --git a/rai/secure/blockstore.hpp b/rai/secure/blockstore.hpp
index 9fb87966..03697086 100644
--- a/rai/secure/blockstore.hpp
+++ b/rai/secure/blockstore.hpp
@@ -254,12 +254,14 @@ public:
 	virtual rai::store_iterator<rai::account, rai::uint128_union> representation_end () = 0;
 
 	virtual void unchecked_clear (rai::transaction const &) = 0;
+	virtual void unchecked_put (rai::transaction const &, rai::unchecked_key const &, std::shared_ptr<rai::block> const &) = 0;
 	virtual void unchecked_put (rai::transaction const &, rai::block_hash const &, std::shared_ptr<rai::block> const &) = 0;
 	virtual std::vector<std::shared_ptr<rai::block>> unchecked_get (rai::transaction const &, rai::block_hash const &) = 0;
-	virtual void unchecked_del (rai::transaction const &, rai::block_hash const &, std::shared_ptr<rai::block>) = 0;
-	virtual rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &) = 0;
-	virtual rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &, rai::block_hash const &) = 0;
-	virtual rai::store_iterator<rai::block_hash, std::shared_ptr<rai::block>> unchecked_end () = 0;
+	virtual bool unchecked_exists (rai::transaction const &, rai::unchecked_key const &) = 0;
+	virtual void unchecked_del (rai::transaction const &, rai::unchecked_key const &) = 0;
+	virtual rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &) = 0;
+	virtual rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> unchecked_begin (rai::transaction const &, rai::unchecked_key const &) = 0;
+	virtual rai::store_iterator<rai::unchecked_key, std::shared_ptr<rai::block>> unchecked_end () = 0;
 	virtual size_t unchecked_count (rai::transaction const &) = 0;
 
 	virtual void checksum_put (rai::transaction const &, uint64_t, uint8_t, rai::checksum const &) = 0;
diff --git a/rai/secure/common.cpp b/rai/secure/common.cpp
index e8b1c541..1b97eb24 100644
--- a/rai/secure/common.cpp
+++ b/rai/secure/common.cpp
@@ -299,6 +299,11 @@ bool rai::pending_key::operator== (rai::pending_key const & other_a) const
 	return account == other_a.account && hash == other_a.hash;
 }
 
+rai::block_hash rai::pending_key::key () const
+{
+	return account;
+}
+
 rai::block_info::block_info () :
 account (0),
 balance (0)
diff --git a/rai/secure/common.hpp b/rai/secure/common.hpp
index 7d37a85f..185c673e 100644
--- a/rai/secure/common.hpp
+++ b/rai/secure/common.hpp
@@ -110,7 +110,11 @@ public:
 	bool operator== (rai::pending_key const &) const;
 	rai::account account;
 	rai::block_hash hash;
+	rai::block_hash key () const;
 };
+// Internally unchecked_key is equal to pending_key (2x uint256_union)
+using unchecked_key = pending_key;
+
 class block_info
 {
 public: