diff --git a/include/boost/http_io/detail/except.hpp b/include/boost/http_io/detail/except.hpp
index de84ec9..f8d9bae 100644
--- a/include/boost/http_io/detail/except.hpp
+++ b/include/boost/http_io/detail/except.hpp
@@ -11,6 +11,7 @@
 #define BOOST_HTTP_IO_DETAIL_EXCEPT_HPP
 
 #include <boost/assert/source_location.hpp>
+#include <boost/http_io/detail/config.hpp>
 
 namespace boost {
 namespace http_io {
diff --git a/include/boost/http_io/impl/read.hpp b/include/boost/http_io/impl/read.hpp
index 7096ff7..9155f01 100644
--- a/include/boost/http_io/impl/read.hpp
+++ b/include/boost/http_io/impl/read.hpp
@@ -16,9 +16,8 @@
 #include <boost/asio/append.hpp>
 #include <boost/asio/compose.hpp>
 #include <boost/asio/coroutine.hpp>
-#include <boost/asio/post.hpp>
+#include <boost/asio/immediate.hpp>
 #include <boost/assert.hpp>
-#include <type_traits>
 
 namespace boost {
 namespace http_io {
@@ -57,13 +56,9 @@ class read_header_op
                 {
                     BOOST_ASIO_HANDLER_LOCATION((
                         __FILE__, __LINE__,
-                        "post"));
-                    asio::post(
-                        stream_.get_executor(),
-                        asio::append(
-                            std::move(self),
-                            ec,
-                            0));
+                        "immediate"));
+                    asio::async_immediate(
+                        self.get_io_executor(), std::move(self));
                 }
                 goto upcall;
             }
@@ -145,13 +140,9 @@ class read_body_op
                 {
                     BOOST_ASIO_HANDLER_LOCATION((
                         __FILE__, __LINE__,
-                        "post"));
-                    asio::post(
-                        stream_.get_executor(),
-                        asio::append(
-                            std::move(self),
-                            ec,
-                            0));
+                        "immediate"));
+                    asio::async_immediate(
+                        self.get_io_executor(), asio::append(std::move(self), ec));
                 }
                 goto upcall;
             }
diff --git a/include/boost/http_io/impl/write.hpp b/include/boost/http_io/impl/write.hpp
index 238ff84..ec77ae0 100644
--- a/include/boost/http_io/impl/write.hpp
+++ b/include/boost/http_io/impl/write.hpp
@@ -14,10 +14,10 @@
 #include <boost/asio/buffer.hpp>
 #include <boost/asio/compose.hpp>
 #include <boost/asio/coroutine.hpp>
-#include <boost/asio/post.hpp>
+#include <boost/asio/immediate.hpp>
 #include <boost/system/error_code.hpp>
 #include <boost/system/result.hpp>
-#include <iterator>
+#include <boost/http_proto/serializer.hpp>
 
 namespace boost {
 namespace http_io {
@@ -43,20 +43,12 @@ class write_some_op
     {
     }
 
-    template<class Self>
-    void
-    operator()(Self& self)
-    {
-        (*this)(self, {}, 0, true);
-    }
-
     template<class Self>
     void
     operator()(
         Self& self,
-        system::error_code ec,
-        std::size_t bytes_transferred,
-        bool do_post = false)
+        system::error_code ec = {},
+        std::size_t bytes_transferred = {})
     {
         system::result<buffers_type> rv;
 
@@ -66,19 +58,13 @@ class write_some_op
             if(! rv)
             {
                 ec = rv.error();
-                if(! do_post)
-                    goto upcall;
                 BOOST_ASIO_CORO_YIELD
                 {
                     BOOST_ASIO_HANDLER_LOCATION((
                         __FILE__, __LINE__,
                         "http_io::write_some_op"));
-                    asio::post(
-                        dest_.get_executor(),
-                        asio::append(
-                            std::move(self),
-                            ec,
-                            bytes_transferred));
+                    asio::async_immediate(
+                        self.get_io_executor(), asio::append(std::move(self), ec));
                 }
                 goto upcall;
             }