diff --git a/include/libtorrent/Makefile.am b/include/libtorrent/Makefile.am
index b6918ae8e..ba9a26c78 100644
--- a/include/libtorrent/Makefile.am
+++ b/include/libtorrent/Makefile.am
@@ -5,7 +5,6 @@ nobase_include_HEADERS = \
   add_torrent_params.hpp       \
   alert.hpp                    \
   alert_manager.hpp            \
-  alert_observer.hpp           \
   alert_types.hpp              \
   alloca.hpp                   \
   allocator.hpp                \
@@ -200,4 +199,3 @@ nobase_include_HEADERS = \
   kademlia/item.hpp                 \
   kademlia/get_item.hpp             \
   kademlia/get_peers.hpp
-
diff --git a/include/libtorrent/alert_observer.hpp b/include/libtorrent/alert_observer.hpp
deleted file mode 100644
index a0d3141d9..000000000
--- a/include/libtorrent/alert_observer.hpp
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
-
-Copyright (c) 2012-2016, Arvid Norberg
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions
-are met:
-
-    * Redistributions of source code must retain the above copyright
-      notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above copyright
-      notice, this list of conditions and the following disclaimer in
-      the documentation and/or other materials provided with the distribution.
-    * Neither the name of the author nor the names of its
-      contributors may be used to endorse or promote products derived
-      from this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGE.
-
-*/
-
-#ifndef TORRENT_ALERT_OBSERVER_HPP_INCLUDED
-#define TORRENT_ALERT_OBSERVER_HPP_INCLUDED
-
-#include <boost/cstdint.hpp>
-
-namespace libtorrent
-{
-
-class alert;
-
-struct alert_observer
-{
-	friend struct alert_handler;
-
-	alert_observer(): num_types(0), flags(0) {}
-	virtual void handle_alert(alert const* a) = 0;
-private:
-	boost::uint8_t types[64];
-	int num_types;
-	int flags;
-};
-
-};
-
-#endif // TORRENT_ALERT_OBSERVER_HPP_INCLUDED
-
diff --git a/src/choker.cpp b/src/choker.cpp
index 103bd9802..1927e1f92 100644
--- a/src/choker.cpp
+++ b/src/choker.cpp
@@ -87,7 +87,7 @@ namespace libtorrent
 		bool c2_quota_complete = !rhs->is_choked() && c2
 			> (std::max)(t2->torrent_file().piece_length() * pieces, 256 * 1024);
 
-		// if c2 has completed a quanta, it shuold be de-prioritized
+		// if c2 has completed a quanta, it should be de-prioritized
 		// and vice versa
 		if (c1_quota_complete < c2_quota_complete) return true;
 		if (c1_quota_complete > c2_quota_complete) return false;
@@ -174,7 +174,7 @@ namespace libtorrent
 
 		// the anti-leech seeding algorithm is based on the paper "Improving
 		// BitTorrent: A Simple Approach" from Chow et. al. and ranks peers based
-		// on how many pieces they have, prefering to unchoke peers that just
+		// on how many pieces they have, preferring to unchoke peers that just
 		// started and peers that are close to completing. Like this:
 		//   ^
 		//   | \                       / |
@@ -417,4 +417,3 @@ namespace libtorrent
 	}
 
 }
-