diff --git a/include/libtorrent/peer_connection.hpp b/include/libtorrent/peer_connection.hpp
index 42ca96f90..1bffa09bc 100644
--- a/include/libtorrent/peer_connection.hpp
+++ b/include/libtorrent/peer_connection.hpp
@@ -538,7 +538,7 @@ namespace libtorrent
 
 		// these functions are virtual to let bt_peer_connection hook into them
 		// and encrypt the content
-		enum message_type_flags { message_type_request = 1 };
+		enum message_type_flags { message_type_request = 1, cork_message = 2 };
 		virtual void send_buffer(char const* begin, int size, int flags = 0
 			, void (*fun)(char*, int, void*) = 0, void* userdata = 0);
 		virtual void setup_send();
diff --git a/src/bt_peer_connection.cpp b/src/bt_peer_connection.cpp
index 93322b346..847467fd1 100644
--- a/src/bt_peer_connection.cpp
+++ b/src/bt_peer_connection.cpp
@@ -2339,12 +2339,12 @@ namespace libtorrent
 			char* ptr = msg;
 			detail::write_int32(r.length + 1 + 4 + 4 + 4 + piece_list_buf.size(), ptr);
 
-			send_buffer(msg, 17);
-			send_buffer(&piece_list_buf[0], piece_list_buf.size());
+			send_buffer(msg, 17, cork_message);
+			send_buffer(&piece_list_buf[0], piece_list_buf.size(), cork_message);
 		}
 		else
 		{
-			send_buffer(msg, 13);
+			send_buffer(msg, 13, cork_message);
 		}
 
 		append_send_buffer(buffer.get(), r.length
diff --git a/src/peer_connection.cpp b/src/peer_connection.cpp
index b4006a3fe..628e3e98a 100644
--- a/src/peer_connection.cpp
+++ b/src/peer_connection.cpp
@@ -4458,7 +4458,6 @@ namespace libtorrent
 		if (j.buffer) m_ses.m_disk_thread.rename_buffer(j.buffer, "dispatched send buffer");
 #endif
 		write_piece(r, buffer);
-		setup_send();
 	}
 
 	void peer_connection::assign_bandwidth(int channel, int amount)
@@ -5005,7 +5004,7 @@ namespace libtorrent
 				, boost::bind(&session_impl::free_buffer, boost::ref(m_ses), _1));
 			++i;
 		}
-		setup_send();
+		if ((flags & cork_message) == 0) setup_send();
 	}
 
 	template<class T>
@@ -5030,7 +5029,7 @@ namespace libtorrent
 		++m_ses.m_num_messages[aux::session_impl::on_read_counter];
 		int size = 8;
 		int index = 0;
-		while (bytes_transferred > size) { size <<= 1; ++index; }
+		while (bytes_transferred > size + 13) { size <<= 1; ++index; }
 		int num_max = sizeof(m_ses.m_recv_buffer_sizes)/sizeof(m_ses.m_recv_buffer_sizes[0]);
 		if (index >= num_max) index = num_max - 1;
 		++m_ses.m_recv_buffer_sizes[index];
@@ -5378,7 +5377,7 @@ namespace libtorrent
 		++m_ses.m_num_messages[aux::session_impl::on_write_counter];
 		int size = 8;
 		int index = 0;
-		while (bytes_transferred > size) { size <<= 1; ++index; }
+		while (bytes_transferred > size + 13) { size <<= 1; ++index; }
 		int num_max = sizeof(m_ses.m_send_buffer_sizes)/sizeof(m_ses.m_send_buffer_sizes[0]);
 		if (index >= num_max) index = num_max - 1;
 		++m_ses.m_send_buffer_sizes[index];