diff --git a/rai/core_test/block_synchronization.cpp b/rai/core_test/block_synchronization.cpp
index 312e61dfc7..055ecb6369 100644
--- a/rai/core_test/block_synchronization.cpp
+++ b/rai/core_test/block_synchronization.cpp
@@ -13,6 +13,7 @@ TEST (pull_synchronization, empty)
 	rai::pull_synchronization sync (test_log, [&blocks] (MDB_txn *, rai::block const & block_a)
 	{
 		blocks.push_back (block_a.clone ());
+		return false;
 	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
@@ -37,6 +38,7 @@ TEST (pull_synchronization, one)
 	rai::pull_synchronization sync (test_log, [&blocks] (MDB_txn *, rai::block const & block_a)
 	{
 		blocks.push_back (block_a.clone ());
+		return false;
 	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
@@ -62,10 +64,11 @@ TEST (pull_synchronization, send_dependencies)
 		store.unchecked_put (transaction, block3.hash (), block3);
 	}
 	rai::pull_synchronization sync (test_log, [&blocks, &store] (MDB_txn * transaction_a, rai::block const & block_a)
-									{
-										store.block_put (transaction_a, block_a.hash (), block_a);
-										blocks.push_back (block_a.clone ());
-									}, store);
+	{
+		store.block_put (transaction_a, block_a.hash (), block_a);
+		blocks.push_back (block_a.clone ());
+		return false;
+	}, store);
 	rai::transaction transaction (store.environment, nullptr, true);
 	ASSERT_FALSE (sync.synchronize (transaction, block3.hash ()));
 	ASSERT_EQ (2, blocks.size ());
@@ -89,10 +92,11 @@ TEST (pull_synchronization, change_dependencies)
 		store.unchecked_put (transaction, block3.hash (), block3);
 	}
 	rai::pull_synchronization sync (test_log, [&blocks, &store] (MDB_txn * transaction_a, rai::block const & block_a)
-									{
-										store.block_put (transaction_a, block_a.hash (), block_a);
-										blocks.push_back (block_a.clone ());
-									}, store);
+	{
+		store.block_put (transaction_a, block_a.hash (), block_a);
+		blocks.push_back (block_a.clone ());
+		return false;
+	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
 		ASSERT_FALSE (sync.synchronize (transaction, block3.hash ()));
@@ -118,10 +122,11 @@ TEST (pull_synchronization, open_dependencies)
 		store.unchecked_put (transaction, block3.hash (), block3);
 	}
 	rai::pull_synchronization sync (test_log, [&blocks, &store] (MDB_txn * transaction_a, rai::block const & block_a)
-									{
-										store.block_put (transaction_a, block_a.hash (), block_a);
-										blocks.push_back (block_a.clone ());
-									}, store);
+	{
+		store.block_put (transaction_a, block_a.hash (), block_a);
+		blocks.push_back (block_a.clone ());
+		return false;
+	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
 		ASSERT_FALSE (sync.synchronize (transaction, block3.hash ()));
@@ -151,10 +156,11 @@ TEST (pull_synchronization, receive_dependencies)
 		store.unchecked_put (transaction, block5.hash (), block5);
 	}
 	rai::pull_synchronization sync (test_log, [&blocks, &store] (MDB_txn * transaction_a, rai::block const & block_a)
-									{
-										store.block_put (transaction_a, block_a.hash (), block_a);
-										blocks.push_back (block_a.clone ());
-									}, store);
+	{
+		store.block_put (transaction_a, block_a.hash (), block_a);
+		blocks.push_back (block_a.clone ());
+		return false;
+	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
 		ASSERT_FALSE (sync.synchronize (transaction, block5.hash ()));
@@ -190,10 +196,11 @@ TEST (pull_synchronization, ladder_dependencies)
 		store.unchecked_put (transaction, block7.hash (), block7);
 	}
 	rai::pull_synchronization sync (test_log, [&blocks, &store] (MDB_txn * transaction_a, rai::block const & block_a)
-									{
-										store.block_put (transaction_a, block_a.hash (), block_a);
-										blocks.push_back (block_a.clone ());
-									}, store);
+	{
+		store.block_put (transaction_a, block_a.hash (), block_a);
+		blocks.push_back (block_a.clone ());
+		return false;
+	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
 		ASSERT_FALSE (sync.synchronize (transaction, block7.hash ()));
@@ -216,6 +223,7 @@ TEST (push_synchronization, empty)
 	rai::push_synchronization sync (test_log, [&blocks] (MDB_txn * transaction_a, rai::block const & block_a)
 	{
 		blocks.push_back (block_a.clone ());
+		return false;
 	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
@@ -238,10 +246,11 @@ TEST (push_synchronization, one)
 		store.block_put (transaction, block2.hash (), block2);
 	}
 	rai::push_synchronization sync (test_log, [&blocks, &store] (MDB_txn * transaction_a, rai::block const & block_a)
-									{
-										store.block_put (transaction_a, block_a.hash (), block_a);
-										blocks.push_back (block_a.clone ());
-									}, store);
+	{
+		store.block_put (transaction_a, block_a.hash (), block_a);
+		blocks.push_back (block_a.clone ());
+		return false;
+	}, store);
 	{
 		rai::transaction transaction (store.environment, nullptr, true);
 		store.unsynced_put (transaction, block2.hash ());
@@ -273,6 +282,7 @@ TEST (pull_synchronization, dependent_fork)
 	store.unchecked_put (transaction, send3.hash (), send3);
 	rai::pull_synchronization sync (test_log, [] (MDB_txn *, rai::block const & block_a)
 	{
+		return false;
 	}, store);
 	ASSERT_FALSE (sync.synchronize (transaction, send3.hash ()));
 }
diff --git a/rai/node/bootstrap.cpp b/rai/node/bootstrap.cpp
index 3cfb95fe42..7b8e686bf1 100644
--- a/rai/node/bootstrap.cpp
+++ b/rai/node/bootstrap.cpp
@@ -5,7 +5,7 @@
 
 #include <boost/log/trivial.hpp>
 
-rai::block_synchronization::block_synchronization (boost::log::sources::logger_mt & log_a, std::function <void (MDB_txn *, rai::block const &)> const & target_a, rai::block_store & store_a) :
+rai::block_synchronization::block_synchronization (boost::log::sources::logger_mt & log_a, std::function <bool (MDB_txn *, rai::block const &)> const & target_a, rai::block_store & store_a) :
 log (log_a),
 target (target_a),
 store (store_a)
@@ -102,7 +102,7 @@ bool rai::block_synchronization::synchronize_one (MDB_txn * transaction_a)
         auto block (retrieve (transaction_a, hash));
         if (block != nullptr)
         {
-			target (transaction_a, *block);
+			result = target (transaction_a, *block);
 		}
 		else
 		{
@@ -125,7 +125,7 @@ bool rai::block_synchronization::synchronize (MDB_txn * transaction_a, rai::bloc
     return result;
 }
 
-rai::pull_synchronization::pull_synchronization (boost::log::sources::logger_mt & log_a, std::function <void (MDB_txn *, rai::block const &)> const & target_a, rai::block_store & store_a) :
+rai::pull_synchronization::pull_synchronization (boost::log::sources::logger_mt & log_a, std::function <bool (MDB_txn *, rai::block const &)> const & target_a, rai::block_store & store_a) :
 block_synchronization (log_a, target_a, store_a)
 {
 }
@@ -140,7 +140,7 @@ bool rai::pull_synchronization::synchronized (MDB_txn * transaction_a, rai::bloc
     return store.block_exists (transaction_a, hash_a) || attempted.count (hash_a) != 0;
 }
 
-rai::push_synchronization::push_synchronization (boost::log::sources::logger_mt & log_a, std::function <void (MDB_txn *, rai::block const &)> const & target_a, rai::block_store & store_a) :
+rai::push_synchronization::push_synchronization (boost::log::sources::logger_mt & log_a, std::function <bool (MDB_txn *, rai::block const &)> const & target_a, rai::block_store & store_a) :
 block_synchronization (log_a, target_a, store_a)
 {
 }
@@ -598,6 +598,7 @@ connection (connection_a),
 synchronization (connection->connection->node->log, [this] (MDB_txn * transaction_a, rai::block const & block_a)
 {
     push_block (block_a);
+	return false;
 }, connection_a->connection->node->store)
 {
 }
diff --git a/rai/node/bootstrap.hpp b/rai/node/bootstrap.hpp
index 86ea0e929b..e66d065695 100644
--- a/rai/node/bootstrap.hpp
+++ b/rai/node/bootstrap.hpp
@@ -14,7 +14,7 @@ namespace rai
 class block_synchronization
 {
 public:
-    block_synchronization (boost::log::sources::logger_mt &, std::function <void (MDB_txn *, rai::block const &)> const &, rai::block_store &);
+    block_synchronization (boost::log::sources::logger_mt &, std::function <bool (MDB_txn *, rai::block const &)> const &, rai::block_store &);
     ~block_synchronization ();
     // Return true if target already has block
     virtual bool synchronized (MDB_txn *, rai::block_hash const &) = 0;
@@ -26,21 +26,21 @@ class block_synchronization
     bool synchronize (MDB_txn *, rai::block_hash const &);
     std::unordered_set <rai::block_hash> sent;
 	boost::log::sources::logger_mt & log;
-    std::function <void (MDB_txn *, rai::block const &)> target;
+    std::function <bool (MDB_txn *, rai::block const &)> target;
     rai::block_store & store;
 	std::unordered_set <rai::block_hash> attempted;
 };
 class pull_synchronization : public rai::block_synchronization
 {
 public:
-    pull_synchronization (boost::log::sources::logger_mt &, std::function <void (MDB_txn *, rai::block const &)> const &, rai::block_store &);
+    pull_synchronization (boost::log::sources::logger_mt &, std::function <bool (MDB_txn *, rai::block const &)> const &, rai::block_store &);
     bool synchronized (MDB_txn *, rai::block_hash const &) override;
     std::unique_ptr <rai::block> retrieve (MDB_txn *, rai::block_hash const &) override;
 };
 class push_synchronization : public rai::block_synchronization
 {
 public:
-    push_synchronization (boost::log::sources::logger_mt &, std::function <void (MDB_txn *, rai::block const &)> const &, rai::block_store &);
+    push_synchronization (boost::log::sources::logger_mt &, std::function <bool (MDB_txn *, rai::block const &)> const &, rai::block_store &);
     bool synchronized (MDB_txn *, rai::block_hash const &) override;
     std::unique_ptr <rai::block> retrieve (MDB_txn *, rai::block_hash const &) override;
 };
diff --git a/rai/node/node.cpp b/rai/node/node.cpp
index b50a3e77e0..c9368c33aa 100755
--- a/rai/node/node.cpp
+++ b/rai/node/node.cpp
@@ -1758,12 +1758,14 @@ void rai::node::process_unchecked (std::shared_ptr <rai::bootstrap_attempt> atte
 		rai::block_hash block (1);  // 1 is a sentinal initial value
 		rai::pull_synchronization synchronization (log, [this, &block, attempt_a] (MDB_txn * transaction_a, rai::block const & block_a)
 		{
-			process_receive_many (transaction_a, block_a, [this, transaction_a, &block, attempt_a] (rai::process_return result_a, rai::block const & block_a)
+			auto result (true);
+			process_receive_many (transaction_a, block_a, [this, transaction_a, &block, attempt_a, &result] (rai::process_return result_a, rai::block const & block_a)
 			{
 				switch (result_a.code)
 				{
 					case rai::process_result::progress:
 					case rai::process_result::old:
+						result = false;
 						// It definitely doesn't need to be in unchecked because it's in the ledger
 						store.unchecked_del (transaction_a, block_a.hash ());
 						break;
@@ -1797,6 +1799,7 @@ void rai::node::process_unchecked (std::shared_ptr <rai::bootstrap_attempt> atte
 						break;
 				}
 			});
+			return result;
 		}, store);
 		while (!block.is_zero ())
 		{