diff --git a/rai/core_test/node.cpp b/rai/core_test/node.cpp
index dc126b6e..44ebddad 100644
--- a/rai/core_test/node.cpp
+++ b/rai/core_test/node.cpp
@@ -1004,10 +1004,10 @@ TEST (node, coherent_observer)
 {
     rai::system system (24000, 1);
     auto & node1 (*system.nodes [0]);
-	node1.observers.blocks.add ([&node1] (rai::block const & block_a, rai::account const & account_a, rai::amount const &)
+	node1.observers.blocks.add ([&node1] (std::shared_ptr <rai::block> block_a, rai::account const & account_a, rai::amount const &)
 	{
 		rai::transaction transaction (node1.store.environment, nullptr, false);
-		ASSERT_TRUE (node1.store.block_exists (transaction, block_a.hash ()));
+		ASSERT_TRUE (node1.store.block_exists (transaction, block_a->hash ()));
 	});
 	system.wallet (0)->insert_adhoc (rai::test_genesis_key.prv);
 	rai::keypair key;
diff --git a/rai/node/node.cpp b/rai/node/node.cpp
index c1b83f20..767e4690 100755
--- a/rai/node/node.cpp
+++ b/rai/node/node.cpp
@@ -1305,15 +1305,15 @@ block_processor (*this)
 	{
 		observers.disconnect ();
 	};
-	observers.blocks.add ([this] (rai::block const & block_a, rai::account const & account_a, rai::amount const & amount_a)
+	observers.blocks.add ([this] (std::shared_ptr <rai::block> block_a, rai::account const & account_a, rai::amount const & amount_a)
 	{
 		if (!config.callback_address.empty ())
 		{
 			boost::property_tree::ptree event;
 			event.add ("account", account_a.to_account ());
-			event.add ("hash", block_a.hash ().to_string ());
+			event.add ("hash", block_a->hash ().to_string ());
 			std::string block_text;
-			block_a.serialize_json (block_text);
+			block_a->serialize_json (block_text);
 			event.add ("block", block_text);
 			event.add ("amount", amount_a.to_string_dec ());
 			std::stringstream ostream;
@@ -1584,7 +1584,7 @@ void rai::node::process_receive_republish (std::shared_ptr <rai::block> incoming
                 node_l->active.start (transaction_a, block_a);
                 node_l->background ([node_l, block_a, result_a] ()
                 {
-                    node_l->observers.blocks (*block_a, result_a.account, result_a.amount);
+                    node_l->observers.blocks (block_a, result_a.account, result_a.amount);
                 });
                 break;
             }
diff --git a/rai/node/node.hpp b/rai/node/node.hpp
index 0295bae7..c4bf078a 100644
--- a/rai/node/node.hpp
+++ b/rai/node/node.hpp
@@ -382,7 +382,7 @@ public:
 class node_observers
 {
 public:
-	rai::observer_set <rai::block const &, rai::account const &, rai::amount const &> blocks;
+	rai::observer_set <std::shared_ptr <rai::block>, rai::account const &, rai::amount const &> blocks;
 	rai::observer_set <rai::account const &, bool> wallet;
 	rai::observer_set <rai::vote const &, rai::endpoint const &> vote;
 	rai::observer_set <rai::endpoint const &> endpoint;
diff --git a/rai/node/rpc.cpp b/rai/node/rpc.cpp
index 04bb22c9..97130b16 100755
--- a/rai/node/rpc.cpp
+++ b/rai/node/rpc.cpp
@@ -77,7 +77,7 @@ node (node_a)
     acceptor.set_option (boost::asio::ip::tcp::acceptor::reuse_address (true));
 	acceptor.bind (endpoint);
 	acceptor.listen ();
-	node_a.observers.blocks.add ([this] (rai::block const & block_a, rai::account const & account_a, rai::amount const &)
+	node_a.observers.blocks.add ([this] (std::shared_ptr <rai::block> block_a, rai::account const & account_a, rai::amount const &)
 	{
 		observer_action (account_a);
 	});
diff --git a/rai/qt/qt.cpp b/rai/qt/qt.cpp
index 1c6740f7..63c732e5 100755
--- a/rai/qt/qt.cpp
+++ b/rai/qt/qt.cpp
@@ -996,7 +996,7 @@ void rai_qt::wallet::start ()
 			this_l->push_main_stack (this_l->send_blocks_window);
 		}
     });
-    node.observers.blocks.add ([this_w] (rai::block const &, rai::account const & account_a, rai::amount const &)
+	node.observers.blocks.add ([this_w] (std::shared_ptr <rai::block>, rai::account const & account_a, rai::amount const &)
     {
 		if (auto this_l = this_w.lock ())
 		{