diff --git a/include/libtorrent/kademlia/observer.hpp b/include/libtorrent/kademlia/observer.hpp
index e033fc20cc7..61ca26d338a 100644
--- a/include/libtorrent/kademlia/observer.hpp
+++ b/include/libtorrent/kademlia/observer.hpp
@@ -57,7 +57,7 @@ struct traversal_algorithm;
 TORRENT_EXTRA_EXPORT void intrusive_ptr_add_ref(observer const*);
 TORRENT_EXTRA_EXPORT void intrusive_ptr_release(observer const*);
 
-struct observer : boost::noncopyable
+struct TORRENT_EXTRA_EXPORT observer : boost::noncopyable
 {
 	friend TORRENT_EXTRA_EXPORT void intrusive_ptr_add_ref(observer const*);
 	friend TORRENT_EXTRA_EXPORT void intrusive_ptr_release(observer const*);
diff --git a/include/libtorrent/kademlia/traversal_algorithm.hpp b/include/libtorrent/kademlia/traversal_algorithm.hpp
index 7e0451af575..9da0c8c11ef 100644
--- a/include/libtorrent/kademlia/traversal_algorithm.hpp
+++ b/include/libtorrent/kademlia/traversal_algorithm.hpp
@@ -58,7 +58,7 @@ class rpc_manager;
 class node;
 
 // this class may not be instantiated as a stack object
-struct traversal_algorithm : boost::noncopyable
+struct TORRENT_EXTRA_EXPORT traversal_algorithm : boost::noncopyable
 {
 	void traverse(node_id const& id, udp::endpoint addr);
 	void finished(observer_ptr o);