diff --git a/src/asio_http2_handler.cc b/src/asio_http2_handler.cc
index d6ba0e01..65d37386 100644
--- a/src/asio_http2_handler.cc
+++ b/src/asio_http2_handler.cc
@@ -33,6 +33,34 @@ namespace nghttp2 {
 
 namespace asio_http2 {
 
+channel::channel()
+  : impl_(util::make_unique<channel_impl>())
+{}
+
+void channel::post(void_cb cb)
+{
+  impl_->post(std::move(cb));
+}
+
+channel_impl& channel::impl()
+{
+  return *impl_;
+}
+
+channel_impl::channel_impl()
+  : strand_(nullptr)
+{}
+
+void channel_impl::post(void_cb cb)
+{
+  strand_->post(std::move(cb));
+}
+
+void channel_impl::strand(boost::asio::io_service::strand *strand)
+{
+  strand_ = strand;
+}
+
 namespace server {
 
 extern std::shared_ptr<std::string> cached_date;
@@ -402,34 +430,6 @@ std::pair<ssize_t, bool> response_impl::call_read
   return std::make_pair(0, true);
 }
 
-channel::channel()
-  : impl_(util::make_unique<channel_impl>())
-{}
-
-void channel::post(void_cb cb)
-{
-  impl_->post(std::move(cb));
-}
-
-channel_impl& channel::impl()
-{
-  return *impl_;
-}
-
-channel_impl::channel_impl()
-  : strand_(nullptr)
-{}
-
-void channel_impl::post(void_cb cb)
-{
-  strand_->post(std::move(cb));
-}
-
-void channel_impl::strand(boost::asio::io_service::strand *strand)
-{
-  strand_ = strand;
-}
-
 http2_stream::http2_stream(int32_t stream_id)
   : request_(std::make_shared<request>()),
     response_(std::make_shared<response>()),
diff --git a/src/asio_http2_handler.h b/src/asio_http2_handler.h
index cbeed227..8bfe6683 100644
--- a/src/asio_http2_handler.h
+++ b/src/asio_http2_handler.h
@@ -40,6 +40,16 @@
 
 namespace nghttp2 {
 namespace asio_http2 {
+
+class channel_impl {
+public:
+  channel_impl();
+  void post(void_cb cb);
+  void strand(boost::asio::io_service::strand *strand);
+private:
+  boost::asio::io_service::strand *strand_;
+};
+
 namespace server {
 
 class http2_handler;
@@ -117,15 +127,6 @@ private:
   bool started_;
 };
 
-class channel_impl {
-public:
-  channel_impl();
-  void post(void_cb cb);
-  void strand(boost::asio::io_service::strand *strand);
-private:
-  boost::asio::io_service::strand *strand_;
-};
-
 class http2_stream {
 public:
   http2_stream(int32_t stream_id);
diff --git a/src/asio_http2_impl.cc b/src/asio_http2_impl.cc
index 728b67a4..a5dd8607 100644
--- a/src/asio_http2_impl.cc
+++ b/src/asio_http2_impl.cc
@@ -153,6 +153,8 @@ void http2_impl::num_concurrent_tasks(size_t num_concurrent_tasks)
   num_concurrent_tasks_ = num_concurrent_tasks;
 }
 
+} // namespace server
+
 template<typename T, typename F>
 std::shared_ptr<util::Defer<T, F>> defer_shared(T&& t, F f)
 {
@@ -206,8 +208,6 @@ std::string http_date(time_t t)
   return util::http_date(t);
 }
 
-} // namespace server
-
 } // namespace asio_http2
 
 } // namespace nghttp2
diff --git a/src/includes/nghttp2/asio_http2.h b/src/includes/nghttp2/asio_http2.h
index cee2da3f..aaca11da 100644
--- a/src/includes/nghttp2/asio_http2.h
+++ b/src/includes/nghttp2/asio_http2.h
@@ -40,11 +40,6 @@ struct header {
   std::string value;
 };
 
-namespace server {
-
-class request_impl;
-class response_impl;
-
 typedef std::function<void(const uint8_t*, std::size_t)> data_cb;
 typedef std::function<void(void)> void_cb;
 
@@ -83,6 +78,11 @@ private:
 
 typedef std::function<void(channel&)> thread_cb;
 
+namespace server {
+
+class request_impl;
+class response_impl;
+
 class request {
 public:
   // Application must not call this directly.
@@ -212,6 +212,8 @@ private:
   std::unique_ptr<http2_impl> impl_;
 };
 
+} // namespace server
+
 // Convenient function to create function to read file denoted by
 // |path|.  This can be passed to response::end().
 read_cb file_reader(const std::string& path);
@@ -233,8 +235,6 @@ std::string percent_decode(const std::string& s);
 // Returns HTTP date representation of current posix time |t|.
 std::string http_date(time_t t);
 
-} // namespace server
-
 } // namespace asio_http2
 
 } // namespace nghttp2