diff --git a/include/libtorrent/io_service.hpp b/include/libtorrent/io_service.hpp
index 9c82dd690..f64673805 100644
--- a/include/libtorrent/io_service.hpp
+++ b/include/libtorrent/io_service.hpp
@@ -39,8 +39,6 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/aux_/disable_warnings_push.hpp"
 
-#include <boost/version.hpp>
-
 #if defined TORRENT_WINDOWS || defined TORRENT_CYGWIN
 // asio assumes that the windows error codes are defined already
 #include <winsock2.h>
@@ -68,5 +66,3 @@ namespace libtorrent
 }
 
 #endif
-
-
diff --git a/include/libtorrent/pe_crypto.hpp b/include/libtorrent/pe_crypto.hpp
index df6c658db..933ffd46d 100644
--- a/include/libtorrent/pe_crypto.hpp
+++ b/include/libtorrent/pe_crypto.hpp
@@ -97,7 +97,7 @@ namespace libtorrent
 		sha1_hash m_xor_mask;
 	};
 
-	struct encryption_handler
+	struct TORRENT_EXTRA_EXPORT encryption_handler
 	{
 		std::tuple<int, span<span<char const>>>
 		encrypt(span<span<char>> iovec);
diff --git a/include/libtorrent/session.hpp b/include/libtorrent/session.hpp
index 779dd2957..cc93b95f2 100644
--- a/include/libtorrent/session.hpp
+++ b/include/libtorrent/session.hpp
@@ -38,16 +38,15 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <thread>
 
 #include "libtorrent/config.hpp"
-#include "libtorrent/version.hpp"
 #include "libtorrent/build_config.hpp"
 #include "libtorrent/io_service.hpp"
 
 #include "libtorrent/storage.hpp"
-#include "libtorrent/session_settings.hpp"
+#include "libtorrent/settings_pack.hpp"
 #include "libtorrent/session_handle.hpp"
 
 #ifndef TORRENT_NO_DEPRECATE
-#include "libtorrent/settings_pack.hpp"
+#include "libtorrent/session_settings.hpp"
 #include "libtorrent/fingerprint.hpp"
 #include <cstdio> // for snprintf
 #endif
@@ -77,7 +76,7 @@ namespace libtorrent
 	// list for torrents. It performs multiple smaller reads when it hashes
 	// pieces, instead of reading it all into memory before hashing.
 	// 
-	// This configuration is inteded to be the starting point for embedded
+	// This configuration is intended to be the starting point for embedded
 	// devices. It will significantly reduce memory usage.
 	// 
 	// ``high_performance_seed`` returns settings optimized for a seed box,
@@ -148,7 +147,7 @@ namespace libtorrent
 	{
 	public:
 
-		// Constructs the session obects which acts as the container of torrents.
+		// Constructs the session objects which acts as the container of torrents.
 		// It provides configuration options across torrents (such as rate limits,
 		// disk cache, ip filter etc.). In order to avoid a race condition between
 		// starting the session and configuring it, you can pass in a
@@ -294,4 +293,3 @@ namespace libtorrent
 }
 
 #endif // TORRENT_SESSION_HPP_INCLUDED
-
diff --git a/include/libtorrent/settings_pack.hpp b/include/libtorrent/settings_pack.hpp
index 2d8a6debb..2ab58804b 100644
--- a/include/libtorrent/settings_pack.hpp
+++ b/include/libtorrent/settings_pack.hpp
@@ -1687,4 +1687,3 @@ namespace libtorrent
 }
 
 #endif
-
diff --git a/src/settings_pack.cpp b/src/settings_pack.cpp
index 31aa12a7c..185b20839 100644
--- a/src/settings_pack.cpp
+++ b/src/settings_pack.cpp
@@ -784,4 +784,3 @@ namespace libtorrent
 		m_bools.clear();
 	}
 }
-
diff --git a/src/udp_socket.cpp b/src/udp_socket.cpp
index 5fdb15621..273946342 100644
--- a/src/udp_socket.cpp
+++ b/src/udp_socket.cpp
@@ -31,13 +31,10 @@ POSSIBILITY OF SUCH DAMAGE.
 */
 
 #include "libtorrent/config.hpp"
-#include "libtorrent/assert.hpp" // for print_backtrace
 #include "libtorrent/socket.hpp"
 #include "libtorrent/udp_socket.hpp"
 #include "libtorrent/socket_io.hpp"
 #include "libtorrent/error.hpp"
-#include "libtorrent/string_util.hpp" // for allocate_string_copy
-#include "libtorrent/broadcast_socket.hpp" // for is_any
 #include "libtorrent/settings_pack.hpp"
 #include "libtorrent/error.hpp"
 #include "libtorrent/aux_/time.hpp" // for aux::time_now()
@@ -49,6 +46,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include <functional>
 #include <array>
+#include <boost/function/function3.hpp>
 #include <boost/system/system_error.hpp>
 #include <boost/system/error_code.hpp>
 #include <boost/asio/read.hpp>
@@ -56,10 +54,6 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/aux_/disable_warnings_pop.hpp"
 
-#if defined TORRENT_ASIO_DEBUGGING
-#include "libtorrent/debug.hpp"
-#endif
-
 namespace libtorrent {
 
 using namespace libtorrent::aux;
@@ -70,7 +64,7 @@ using namespace std::placeholders;
 //
 // 1. since its asynchronous functions may refer to it after the udp_socket has
 //    been destructed, it needs to be held by a shared_ptr
-// 2. since using a sokcs proxy is assumed to be a less common case, it makes
+// 2. since using a socks proxy is assumed to be a less common case, it makes
 //    the common case cheaper by not allocating this space unconditionally
 struct socks5 : boost::enable_shared_from_this<socks5>
 {
@@ -762,4 +756,3 @@ void socks5::close()
 }
 
 }
-