diff --git a/libtorrent/include/libtorrent/asio/buffer.hpp b/libtorrent/include/libtorrent/asio/buffer.hpp
index 384e8d70a..7e5dc76c8 100644
--- a/libtorrent/include/libtorrent/asio/buffer.hpp
+++ b/libtorrent/include/libtorrent/asio/buffer.hpp
@@ -117,7 +117,7 @@ namespace detail {
 inline void* buffer_cast_helper(const mutable_buffer& b)
 {
 #if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
-  if (b.debug_check_)
+  if (b.size_ && b.debug_check_)
     b.debug_check_();
 #endif // ASIO_ENABLE_BUFFER_DEBUGGING
   return b.data_;
@@ -281,7 +281,7 @@ namespace detail {
 inline const void* buffer_cast_helper(const const_buffer& b)
 {
 #if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
-  if (b.debug_check_)
+  if (b.size_ && b.debug_check_)
     b.debug_check_();
 #endif // ASIO_ENABLE_BUFFER_DEBUGGING
   return b.data_;
diff --git a/libtorrent/include/libtorrent/asio/completion_condition.hpp b/libtorrent/include/libtorrent/asio/completion_condition.hpp
index 42696d599..939a4a8f3 100644
--- a/libtorrent/include/libtorrent/asio/completion_condition.hpp
+++ b/libtorrent/include/libtorrent/asio/completion_condition.hpp
@@ -71,6 +71,28 @@ private:
 /// Return a completion condition function object that indicates that a read or
 /// write operation should continue until all of the data has been transferred,
 /// or until an error occurs.
+/**
+ * This function is used to create an object, of unspecified type, that meets
+ * CompletionCondition requirements.
+ *
+ * @par Example
+ * Reading until a buffer is full:
+ * @code
+ * boost::array<char, 128> buf;
+ * asio::error_code ec;
+ * std::size_t n = asio::read(
+ *     sock, asio::buffer(buf),
+ *     asio::transfer_all(), ec);
+ * if (ec)
+ * {
+ *   // An error occurred.
+ * }
+ * else
+ * {
+ *   // n == 128
+ * }
+ * @endcode
+ */
 #if defined(GENERATING_DOCUMENTATION)
 unspecified transfer_all();
 #else
@@ -83,6 +105,28 @@ inline detail::transfer_all_t transfer_all()
 /// Return a completion condition function object that indicates that a read or
 /// write operation should continue until a minimum number of bytes has been
 /// transferred, or until an error occurs.
+/**
+ * This function is used to create an object, of unspecified type, that meets
+ * CompletionCondition requirements.
+ *
+ * @par Example
+ * Reading until a buffer is full or contains at least 64 bytes:
+ * @code
+ * boost::array<char, 128> buf;
+ * asio::error_code ec;
+ * std::size_t n = asio::read(
+ *     sock, asio::buffer(buf),
+ *     asio::transfer_at_least(64), ec);
+ * if (ec)
+ * {
+ *   // An error occurred.
+ * }
+ * else
+ * {
+ *   // n >= 64 && n <= 128
+ * }
+ * @endcode
+ */
 #if defined(GENERATING_DOCUMENTATION)
 unspecified transfer_at_least(std::size_t minimum);
 #else
diff --git a/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp b/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp
index d55e86454..9c406c3fa 100644
--- a/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp
@@ -331,7 +331,10 @@ public:
   std::size_t cancel_timer(timer_queue<Time_Traits>& timer_queue, void* token)
   {
     asio::detail::mutex::scoped_lock lock(mutex_);
-    return timer_queue.cancel_timer(token);
+    std::size_t n = timer_queue.cancel_timer(token);
+    if (n > 0)
+      interrupter_.interrupt();
+    return n;
   }
 
 private:
@@ -347,16 +350,13 @@ private:
     read_op_queue_.dispatch_cancellations();
     write_op_queue_.dispatch_cancellations();
     except_op_queue_.dispatch_cancellations();
+    for (std::size_t i = 0; i < timer_queues_.size(); ++i)
+      timer_queues_[i]->dispatch_cancellations();
 
     // Check if the thread is supposed to stop.
     if (stop_thread_)
     {
-      // Clean up operations. We must not hold the lock since the operations may
-      // make calls back into this reactor.
-      lock.unlock();
-      read_op_queue_.cleanup_operations();
-      write_op_queue_.cleanup_operations();
-      except_op_queue_.cleanup_operations();
+      cleanup_operations_and_timers(lock);
       return;
     }
 
@@ -365,12 +365,7 @@ private:
     if (!block && read_op_queue_.empty() && write_op_queue_.empty()
         && except_op_queue_.empty() && all_timer_queues_are_empty())
     {
-      // Clean up operations. We must not hold the lock since the operations may
-      // make calls back into this reactor.
-      lock.unlock();
-      read_op_queue_.cleanup_operations();
-      write_op_queue_.cleanup_operations();
-      except_op_queue_.cleanup_operations();
+      cleanup_operations_and_timers(lock);
       return;
     }
 
@@ -398,59 +393,44 @@ private:
       }
       else
       {
-        if (events[i].events & (EPOLLERR | EPOLLHUP))
+        bool more_reads = false;
+        bool more_writes = false;
+        bool more_except = false;
+        asio::error_code ec;
+
+        // Exception operations must be processed first to ensure that any
+        // out-of-band data is read before normal data.
+        if (events[i].events & (EPOLLPRI | EPOLLERR | EPOLLHUP))
+          more_except = except_op_queue_.dispatch_operation(descriptor, ec);
+        else
+          more_except = except_op_queue_.has_operation(descriptor);
+
+        if (events[i].events & (EPOLLIN | EPOLLERR | EPOLLHUP))
+          more_reads = read_op_queue_.dispatch_operation(descriptor, ec);
+        else
+          more_reads = read_op_queue_.has_operation(descriptor);
+
+        if (events[i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP))
+          more_writes = write_op_queue_.dispatch_operation(descriptor, ec);
+        else
+          more_writes = write_op_queue_.has_operation(descriptor);
+
+        epoll_event ev = { 0, { 0 } };
+        ev.events = EPOLLERR | EPOLLHUP;
+        if (more_reads)
+          ev.events |= EPOLLIN;
+        if (more_writes)
+          ev.events |= EPOLLOUT;
+        if (more_except)
+          ev.events |= EPOLLPRI;
+        ev.data.fd = descriptor;
+        int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
+        if (result != 0)
         {
-          asio::error_code ec;
-          except_op_queue_.dispatch_all_operations(descriptor, ec);
+          ec = asio::error_code(errno, asio::native_ecat);
           read_op_queue_.dispatch_all_operations(descriptor, ec);
           write_op_queue_.dispatch_all_operations(descriptor, ec);
-
-          epoll_event ev = { 0, { 0 } };
-          ev.events = 0;
-          ev.data.fd = descriptor;
-          epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
-        }
-        else
-        {
-          bool more_reads = false;
-          bool more_writes = false;
-          bool more_except = false;
-          asio::error_code ec;
-
-          // Exception operations must be processed first to ensure that any
-          // out-of-band data is read before normal data.
-          if (events[i].events & EPOLLPRI)
-            more_except = except_op_queue_.dispatch_operation(descriptor, ec);
-          else
-            more_except = except_op_queue_.has_operation(descriptor);
-
-          if (events[i].events & EPOLLIN)
-            more_reads = read_op_queue_.dispatch_operation(descriptor, ec);
-          else
-            more_reads = read_op_queue_.has_operation(descriptor);
-
-          if (events[i].events & EPOLLOUT)
-            more_writes = write_op_queue_.dispatch_operation(descriptor, ec);
-          else
-            more_writes = write_op_queue_.has_operation(descriptor);
-
-          epoll_event ev = { 0, { 0 } };
-          ev.events = EPOLLERR | EPOLLHUP;
-          if (more_reads)
-            ev.events |= EPOLLIN;
-          if (more_writes)
-            ev.events |= EPOLLOUT;
-          if (more_except)
-            ev.events |= EPOLLPRI;
-          ev.data.fd = descriptor;
-          int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
-          if (result != 0)
-          {
-            ec = asio::error_code(errno, asio::native_ecat);
-            read_op_queue_.dispatch_all_operations(descriptor, ec);
-            write_op_queue_.dispatch_all_operations(descriptor, ec);
-            except_op_queue_.dispatch_all_operations(descriptor, ec);
-          }
+          except_op_queue_.dispatch_all_operations(descriptor, ec);
         }
       }
     }
@@ -458,19 +438,17 @@ private:
     write_op_queue_.dispatch_cancellations();
     except_op_queue_.dispatch_cancellations();
     for (std::size_t i = 0; i < timer_queues_.size(); ++i)
+    {
       timer_queues_[i]->dispatch_timers();
+      timer_queues_[i]->dispatch_cancellations();
+    }
 
     // Issue any pending cancellations.
     for (size_t i = 0; i < pending_cancellations_.size(); ++i)
       cancel_ops_unlocked(pending_cancellations_[i]);
     pending_cancellations_.clear();
 
-    // Clean up operations. We must not hold the lock since the operations may
-    // make calls back into this reactor.
-    lock.unlock();
-    read_op_queue_.cleanup_operations();
-    write_op_queue_.cleanup_operations();
-    except_op_queue_.cleanup_operations();
+    cleanup_operations_and_timers(lock);
   }
 
   // Run the select loop in the thread.
@@ -566,6 +544,22 @@ private:
       interrupter_.interrupt();
   }
 
+  // Clean up operations and timers. We must not hold the lock since the
+  // destructors may make calls back into this reactor. We make a copy of the
+  // vector of timer queues since the original may be modified while the lock
+  // is not held.
+  void cleanup_operations_and_timers(
+      asio::detail::mutex::scoped_lock& lock)
+  {
+    timer_queues_for_cleanup_ = timer_queues_;
+    lock.unlock();
+    read_op_queue_.cleanup_operations();
+    write_op_queue_.cleanup_operations();
+    except_op_queue_.cleanup_operations();
+    for (std::size_t i = 0; i < timer_queues_for_cleanup_.size(); ++i)
+      timer_queues_for_cleanup_[i]->cleanup_timers();
+  }
+
   // Mutex to protect access to internal data.
   asio::detail::mutex mutex_;
 
@@ -590,6 +584,10 @@ private:
   // The timer queues.
   std::vector<timer_queue_base*> timer_queues_;
 
+  // A copy of the timer queues, used when cleaning up timers. The copy is
+  // stored as a class data member to avoid unnecessary memory allocation.
+  std::vector<timer_queue_base*> timer_queues_for_cleanup_;
+
   // The descriptors that are pending cancellation.
   std::vector<socket_type> pending_cancellations_;
 
diff --git a/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp b/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp
index 6628803af..18a842b46 100644
--- a/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp
@@ -321,7 +321,10 @@ public:
   std::size_t cancel_timer(timer_queue<Time_Traits>& timer_queue, void* token)
   {
     asio::detail::mutex::scoped_lock lock(mutex_);
-    return timer_queue.cancel_timer(token);
+    std::size_t n = timer_queue.cancel_timer(token);
+    if (n > 0)
+      interrupter_.interrupt();
+    return n;
   }
 
 private:
@@ -337,16 +340,13 @@ private:
     read_op_queue_.dispatch_cancellations();
     write_op_queue_.dispatch_cancellations();
     except_op_queue_.dispatch_cancellations();
+    for (std::size_t i = 0; i < timer_queues_.size(); ++i)
+      timer_queues_[i]->dispatch_cancellations();
 
     // Check if the thread is supposed to stop.
     if (stop_thread_)
     {
-      // Clean up operations. We must not hold the lock since the operations may
-      // make calls back into this reactor.
-      lock.unlock();
-      read_op_queue_.cleanup_operations();
-      write_op_queue_.cleanup_operations();
-      except_op_queue_.cleanup_operations();
+      cleanup_operations_and_timers(lock);
       return;
     }
 
@@ -355,12 +355,7 @@ private:
     if (!block && read_op_queue_.empty() && write_op_queue_.empty()
         && except_op_queue_.empty() && all_timer_queues_are_empty())
     {
-      // Clean up operations. We must not hold the lock since the operations may
-      // make calls back into this reactor.
-      lock.unlock();
-      read_op_queue_.cleanup_operations();
-      write_op_queue_.cleanup_operations();
-      except_op_queue_.cleanup_operations();
+      cleanup_operations_and_timers(lock);
       return;
     }
 
@@ -466,19 +461,17 @@ private:
     write_op_queue_.dispatch_cancellations();
     except_op_queue_.dispatch_cancellations();
     for (std::size_t i = 0; i < timer_queues_.size(); ++i)
+    {
       timer_queues_[i]->dispatch_timers();
+      timer_queues_[i]->dispatch_cancellations();
+    }
 
     // Issue any pending cancellations.
     for (std::size_t i = 0; i < pending_cancellations_.size(); ++i)
       cancel_ops_unlocked(pending_cancellations_[i]);
     pending_cancellations_.clear();
 
-    // Clean up operations. We must not hold the lock since the operations may
-    // make calls back into this reactor.
-    lock.unlock();
-    read_op_queue_.cleanup_operations();
-    write_op_queue_.cleanup_operations();
-    except_op_queue_.cleanup_operations();
+    cleanup_operations_and_timers(lock);
   }
 
   // Run the select loop in the thread.
@@ -573,6 +566,22 @@ private:
       interrupter_.interrupt();
   }
 
+  // Clean up operations and timers. We must not hold the lock since the
+  // destructors may make calls back into this reactor. We make a copy of the
+  // vector of timer queues since the original may be modified while the lock
+  // is not held.
+  void cleanup_operations_and_timers(
+      asio::detail::mutex::scoped_lock& lock)
+  {
+    timer_queues_for_cleanup_ = timer_queues_;
+    lock.unlock();
+    read_op_queue_.cleanup_operations();
+    write_op_queue_.cleanup_operations();
+    except_op_queue_.cleanup_operations();
+    for (std::size_t i = 0; i < timer_queues_for_cleanup_.size(); ++i)
+      timer_queues_for_cleanup_[i]->cleanup_timers();
+  }
+
   // Mutex to protect access to internal data.
   asio::detail::mutex mutex_;
 
@@ -597,6 +606,10 @@ private:
   // The timer queues.
   std::vector<timer_queue_base*> timer_queues_;
 
+  // A copy of the timer queues, used when cleaning up timers. The copy is
+  // stored as a class data member to avoid unnecessary memory allocation.
+  std::vector<timer_queue_base*> timer_queues_for_cleanup_;
+
   // The descriptors that are pending cancellation.
   std::vector<socket_type> pending_cancellations_;
 
diff --git a/libtorrent/include/libtorrent/asio/detail/select_reactor.hpp b/libtorrent/include/libtorrent/asio/detail/select_reactor.hpp
index 83f093ae6..079ec2de8 100644
--- a/libtorrent/include/libtorrent/asio/detail/select_reactor.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/select_reactor.hpp
@@ -229,7 +229,10 @@ public:
   std::size_t cancel_timer(timer_queue<Time_Traits>& timer_queue, void* token)
   {
     asio::detail::mutex::scoped_lock lock(mutex_);
-    return timer_queue.cancel_timer(token);
+    std::size_t n = timer_queue.cancel_timer(token);
+    if (n > 0)
+      interrupter_.interrupt();
+    return n;
   }
 
 private:
@@ -245,16 +248,13 @@ private:
     read_op_queue_.dispatch_cancellations();
     write_op_queue_.dispatch_cancellations();
     except_op_queue_.dispatch_cancellations();
+    for (std::size_t i = 0; i < timer_queues_.size(); ++i)
+      timer_queues_[i]->dispatch_cancellations();
 
     // Check if the thread is supposed to stop.
     if (stop_thread_)
     {
-      // Clean up operations. We must not hold the lock since the operations may
-      // make calls back into this reactor.
-      lock.unlock();
-      read_op_queue_.cleanup_operations();
-      write_op_queue_.cleanup_operations();
-      except_op_queue_.cleanup_operations();
+      cleanup_operations_and_timers(lock);
       return;
     }
 
@@ -263,12 +263,7 @@ private:
     if (!block && read_op_queue_.empty() && write_op_queue_.empty()
         && except_op_queue_.empty() && all_timer_queues_are_empty())
     {
-      // Clean up operations. We must not hold the lock since the operations may
-      // make calls back into this reactor.
-      lock.unlock();
-      read_op_queue_.cleanup_operations();
-      write_op_queue_.cleanup_operations();
-      except_op_queue_.cleanup_operations();
+      cleanup_operations_and_timers(lock);
       return;
     }
 
@@ -321,19 +316,17 @@ private:
       write_op_queue_.dispatch_cancellations();
     }
     for (std::size_t i = 0; i < timer_queues_.size(); ++i)
+    {
       timer_queues_[i]->dispatch_timers();
+      timer_queues_[i]->dispatch_cancellations();
+    }
 
     // Issue any pending cancellations.
     for (size_t i = 0; i < pending_cancellations_.size(); ++i)
       cancel_ops_unlocked(pending_cancellations_[i]);
     pending_cancellations_.clear();
 
-    // Clean up operations. We must not hold the lock since the operations may
-    // make calls back into this reactor.
-    lock.unlock();
-    read_op_queue_.cleanup_operations();
-    write_op_queue_.cleanup_operations();
-    except_op_queue_.cleanup_operations();
+    cleanup_operations_and_timers(lock);
   }
 
   // Run the select loop in the thread.
@@ -414,6 +407,22 @@ private:
       interrupter_.interrupt();
   }
 
+  // Clean up operations and timers. We must not hold the lock since the
+  // destructors may make calls back into this reactor. We make a copy of the
+  // vector of timer queues since the original may be modified while the lock
+  // is not held.
+  void cleanup_operations_and_timers(
+      asio::detail::mutex::scoped_lock& lock)
+  {
+    timer_queues_for_cleanup_ = timer_queues_;
+    lock.unlock();
+    read_op_queue_.cleanup_operations();
+    write_op_queue_.cleanup_operations();
+    except_op_queue_.cleanup_operations();
+    for (std::size_t i = 0; i < timer_queues_for_cleanup_.size(); ++i)
+      timer_queues_for_cleanup_[i]->cleanup_timers();
+  }
+
   // Mutex to protect access to internal data.
   asio::detail::mutex mutex_;
 
@@ -435,6 +444,10 @@ private:
   // The timer queues.
   std::vector<timer_queue_base*> timer_queues_;
 
+  // A copy of the timer queues, used when cleaning up timers. The copy is
+  // stored as a class data member to avoid unnecessary memory allocation.
+  std::vector<timer_queue_base*> timer_queues_for_cleanup_;
+
   // The descriptors that are pending cancellation.
   std::vector<socket_type> pending_cancellations_;
 
diff --git a/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp b/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp
index 4b38c6ee8..7f4e15edf 100644
--- a/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp
@@ -1504,6 +1504,12 @@ inline asio::error_code translate_addrinfo_error(int error)
   case EAI_MEMORY:
     return asio::error::no_memory;
   case EAI_NONAME:
+#if defined(EAI_ADDRFAMILY)
+  case EAI_ADDRFAMILY:
+#endif
+#if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME)
+  case EAI_NODATA:
+#endif
     return asio::error::host_not_found;
   case EAI_SERVICE:
     return asio::error::service_not_found;
diff --git a/libtorrent/include/libtorrent/asio/detail/timer_queue.hpp b/libtorrent/include/libtorrent/asio/detail/timer_queue.hpp
index af1e36bd5..7735e87cf 100644
--- a/libtorrent/include/libtorrent/asio/detail/timer_queue.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/timer_queue.hpp
@@ -48,7 +48,9 @@ public:
   // Constructor.
   timer_queue()
     : timers_(),
-      heap_()
+      heap_(),
+      cancelled_timers_(0),
+      cleanup_timers_(0)
   {
   }
 
@@ -111,12 +113,17 @@ public:
     {
       timer_base* t = heap_[0];
       remove_timer(t);
+      t->prev_ = 0;
+      t->next_ = cleanup_timers_;
+      cleanup_timers_ = t;
       t->invoke(asio::error_code());
     }
   }
 
-  // Cancel the timer with the given token. The handler will be invoked
-  // immediately with the result operation_aborted.
+  // Cancel the timers with the given token. Any timers pending for the token
+  // will be notified that they have been cancelled next time
+  // dispatch_cancellations is called. Returns the number of timers that were
+  // cancelled.
   std::size_t cancel_timer(void* timer_token)
   {
     std::size_t num_cancelled = 0;
@@ -129,7 +136,9 @@ public:
       {
         timer_base* next = t->next_;
         remove_timer(t);
-        t->invoke(asio::error::operation_aborted);
+        t->prev_ = 0;
+        t->next_ = cancelled_timers_;
+        cancelled_timers_ = t;
         t = next;
         ++num_cancelled;
       }
@@ -137,6 +146,31 @@ public:
     return num_cancelled;
   }
 
+  // Dispatch any pending cancels for timers.
+  virtual void dispatch_cancellations()
+  {
+    while (cancelled_timers_)
+    {
+      timer_base* this_timer = cancelled_timers_;
+      cancelled_timers_ = this_timer->next_;
+      this_timer->next_ = cleanup_timers_;
+      cleanup_timers_ = this_timer;
+      this_timer->invoke(asio::error::operation_aborted);
+    }
+  }
+
+  // Destroy timers that are waiting to be cleaned up.
+  virtual void cleanup_timers()
+  {
+    while (cleanup_timers_)
+    {
+      timer_base* next_timer = cleanup_timers_->next_;
+      cleanup_timers_->next_ = 0;
+      cleanup_timers_->destroy();
+      cleanup_timers_ = next_timer;
+    }
+  }
+
   // Destroy all timers.
   virtual void destroy_timers()
   {
@@ -151,6 +185,7 @@ public:
     }
     heap_.clear();
     timers_.clear();
+    cleanup_timers();
   }
 
 private:
@@ -238,8 +273,7 @@ private:
     static void invoke_handler(timer_base* base,
         const asio::error_code& result)
     {
-      std::auto_ptr<timer<Handler> > t(static_cast<timer<Handler>*>(base));
-      t->handler_(result);
+      static_cast<timer<Handler>*>(base)->handler_(result);
     }
 
     // Destroy the handler.
@@ -338,6 +372,12 @@ private:
 
   // The heap of timers, with the earliest timer at the front.
   std::vector<timer_base*> heap_;
+
+  // The list of timers to be cancelled.
+  timer_base* cancelled_timers_;
+
+  // The list of timers to be destroyed.
+  timer_base* cleanup_timers_;
 };
 
 } // namespace detail
diff --git a/libtorrent/include/libtorrent/asio/detail/timer_queue_base.hpp b/libtorrent/include/libtorrent/asio/detail/timer_queue_base.hpp
index c8be49748..6cf25747a 100644
--- a/libtorrent/include/libtorrent/asio/detail/timer_queue_base.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/timer_queue_base.hpp
@@ -44,6 +44,12 @@ public:
   // Dispatch all ready timers.
   virtual void dispatch_timers() = 0;
 
+  // Dispatch any pending cancels for timers.
+  virtual void dispatch_cancellations() = 0;
+
+  // Destroy timers that are waiting to be cleaned up.
+  virtual void cleanup_timers() = 0;
+
   // Destroy all timers.
   virtual void destroy_timers() = 0;
 };
diff --git a/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service_fwd.hpp b/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service_fwd.hpp
index 184fdfa18..26eacae2a 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service_fwd.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service_fwd.hpp
@@ -21,6 +21,8 @@
 #include <boost/config.hpp>
 #include "asio/detail/pop_options.hpp"
 
+#include "asio/detail/socket_types.hpp"
+
 // This service is only supported on Win32 (NT4 and later).
 #if !defined(ASIO_DISABLE_IOCP)
 #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
diff --git a/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp b/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp
index 007286e8d..d0078978a 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp
@@ -1950,26 +1950,29 @@ public:
   }
 
 private:
-  // Helper function to provide InterlockedCompareExchangePointer functionality
-  // on very old Platform SDKs.
+  // Helper function to emulate InterlockedCompareExchangePointer functionality
+  // for:
+  // - very old Platform SDKs; and
+  // - platform SDKs where MSVC's /Wp64 option causes spurious warnings.
   void* interlocked_compare_exchange_pointer(void** dest, void* exch, void* cmp)
   {
-#if defined(_WIN32_WINNT) && (_WIN32_WINNT <= 0x400) && (_M_IX86)
+#if defined(_M_IX86)
     return reinterpret_cast<void*>(InterlockedCompareExchange(
-          reinterpret_cast<LONG*>(dest), reinterpret_cast<LONG>(exch),
+          reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(exch),
           reinterpret_cast<LONG>(cmp)));
 #else
     return InterlockedCompareExchangePointer(dest, exch, cmp);
 #endif
   }
 
-  // Helper function to provide InterlockedExchangePointer functionality on very
-  // old Platform SDKs.
+  // Helper function to emulate InterlockedExchangePointer functionality for:
+  // - very old Platform SDKs; and
+  // - platform SDKs where MSVC's /Wp64 option causes spurious warnings.
   void* interlocked_exchange_pointer(void** dest, void* val)
   {
-#if defined(_WIN32_WINNT) && (_WIN32_WINNT <= 0x400) && (_M_IX86)
+#if defined(_M_IX86)
     return reinterpret_cast<void*>(InterlockedExchange(
-          reinterpret_cast<LONG*>(dest), reinterpret_cast<LONG>(val)));
+          reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(val)));
 #else
     return InterlockedExchangePointer(dest, val);
 #endif