diff --git a/doc/4_02_message.qbk b/doc/4_02_message.qbk
index d21064de..c8ddd429 100644
--- a/doc/4_02_message.qbk
+++ b/doc/4_02_message.qbk
@@ -51,7 +51,7 @@ This diagram shows the inheritance relationship between header and message,
 along with the fields from the different partial specializations for each
 possible value of `isRequest`:
 
-[$images/message.png [width 711px] [height 424px]]
+[$images/message.png [width 730px] [height 410px]]
 
 For notational convenience, the template type aliases 
 [link beast.ref.http__request `request`] and
@@ -126,9 +126,9 @@ objects:
     req.version = 11;   // HTTP/1.1
     req.method(verb::get);
     req.target("/index.htm");
-    req.fields.insert("Accept", "text/html");
-    req.fields.insert("Connection", "keep-alive");
-    req.fields.insert("User-Agent", "Beast");
+    req.insert("Accept", "text/html");
+    req.insert("Connection", "keep-alive");
+    req.insert("User-Agent", "Beast");
 ```
 ][
 ```
@@ -149,8 +149,8 @@ objects:
     res.version = 11;   // HTTP/1.1
     res.result(status::ok);
     res.body = "Hello, world!";
-    res.fields.insert("Server", "Beast");
-    res.fields.insert("Content-Length", res.body.size());
+    res.insert("Server", "Beast");
+    res.insert("Content-Length", res.body.size());
 ```
 ][
 ```
diff --git a/doc/4_03_streams.qbk b/doc/4_03_streams.qbk
index 10be7a88..e8b180d9 100644
--- a/doc/4_03_streams.qbk
+++ b/doc/4_03_streams.qbk
@@ -129,7 +129,7 @@ the number of octets received prior to the server closing the connection:
         response<string_body> res;
         res.version = 11;
         res.result(status::ok);
-        res.fields.insert("Server", "Beast");
+        res.insert("Server", "Beast");
         res.body = "Hello, world!";
 
         error_code ec;
diff --git a/doc/6_3_client.qbk b/doc/6_3_client.qbk
index 2f69bb86..bef35c9d 100644
--- a/doc/6_3_client.qbk
+++ b/doc/6_3_client.qbk
@@ -61,7 +61,7 @@ on the request:
 ```
     void decorate(websocket::request_type& req)
     {
-        req.fields.insert("Sec-WebSocket-Protocol", "xmpp;ws-chat");
+        req.insert("Sec-WebSocket-Protocol", "xmpp;ws-chat");
     }
     ...
     ws.handshake_ex("localhost", "/", &decorate);
@@ -102,7 +102,7 @@ as follows:
 ```
     websocket::response_type res;
     ws.handshake(res, "localhost", "/");
-    if(! res.fields.exists("Sec-WebSocket-Protocol"))
+    if(! res.exists("Sec-WebSocket-Protocol"))
         throw std::invalid_argument("missing subprotocols");
 ```
 
diff --git a/doc/6_4_server.qbk b/doc/6_4_server.qbk
index d7ee2071..18bcfe6a 100644
--- a/doc/6_4_server.qbk
+++ b/doc/6_4_server.qbk
@@ -53,7 +53,7 @@ field on the response:
     ws.accept_ex(
         [](websocket::response_type& res)
         {
-            res.fields.insert("Server", "AcmeServer");
+            res.insert("Server", "AcmeServer");
         });
 
 ```
diff --git a/doc/images/message.png b/doc/images/message.png
index 159df8c0..0ee1fe6e 100644
Binary files a/doc/images/message.png and b/doc/images/message.png differ
diff --git a/examples/doc_http_samples.hpp b/examples/doc_http_samples.hpp
index 95b7dfe0..af6c9315 100644
--- a/examples/doc_http_samples.hpp
+++ b/examples/doc_http_samples.hpp
@@ -61,7 +61,7 @@ send_expect_100_continue(
         "DynamicBuffer requirements not met");
 
     // Insert or replace the Expect field
-    req.fields.replace("Expect", "100-continue");
+    req.replace("Expect", "100-continue");
 
     // Create the serializer
     auto sr = make_serializer(req);
@@ -130,13 +130,13 @@ receive_expect_100_continue(
         return;
 
     // Check for the Expect field value
-    if(parser.get().fields["Expect"] == "100-continue")
+    if(parser.get()["Expect"] == "100-continue")
     {
         // send 100 response
         response<empty_body> res;
         res.version = 11;
         res.result(status::continue_);
-        res.fields.insert("Server", "test");
+        res.insert("Server", "test");
         write(stream, res, ec);
         if(ec)
             return;
@@ -198,8 +198,8 @@ send_cgi_response(
 
     res.result(status::ok);
     res.version = 11;
-    res.fields.insert("Server", "Beast");
-    res.fields.insert("Transfer-Encoding", "chunked");
+    res.insert("Server", "Beast");
+    res.insert("Transfer-Encoding", "chunked");
 
     // No data yet, but we set more = true to indicate
     // that it might be coming later. Otherwise the
@@ -307,7 +307,7 @@ void do_server_head(
     // Set up the response, starting with the common fields
     response<string_body> res;
     res.version = 11;
-    res.fields.insert("Server", "test");
+    res.insert("Server", "test");
 
     // Now handle request-specific fields
     switch(req.method())
@@ -319,7 +319,7 @@ void do_server_head(
         // set of headers that would be sent for a GET request,
         // including the Content-Length, except for the body.
         res.result(status::ok);
-        res.fields.insert("Content-Length", payload.size());
+        res.insert("Content-Length", payload.size());
 
         // For GET requests, we include the body
         if(req.method() == verb::get)
@@ -337,7 +337,7 @@ void do_server_head(
         // We return responses indicating an error if
         // we do not recognize the request method.
         res.result(status::bad_request);
-        res.fields.insert("Content-Type", "text/plain");
+        res.insert("Content-Type", "text/plain");
         res.body = "Invalid request-method '" + req.method_string().to_string() + "'";
         break;
     }
@@ -397,11 +397,11 @@ do_head_request(
     req.version = 11;
     req.method(verb::head);
     req.target(target);
-    req.fields.insert("User-Agent", "test");
+    req.insert("User-Agent", "test");
 
     // A client MUST send a Host header field in all HTTP/1.1 request messages.
     // https://tools.ietf.org/html/rfc7230#section-5.4
-    req.fields.insert("Host", "localhost");
+    req.insert("Host", "localhost");
 
     // Now send it
     write(stream, req, ec);
@@ -813,8 +813,8 @@ do_form_request(
     case verb::post:
     {
         // If this is not a form upload then use a string_body
-        if( req0.get().fields["Content-Type"] != "application/x-www-form-urlencoded" &&
-            req0.get().fields["Content-Type"] != "multipart/form-data")
+        if( req0.get()["Content-Type"] != "application/x-www-form-urlencoded" &&
+            req0.get()["Content-Type"] != "multipart/form-data")
             goto do_string_body;
 
         // Commit to string_body as the body type.
diff --git a/examples/http_async_server.hpp b/examples/http_async_server.hpp
index 82998566..a1af3133 100644
--- a/examples/http_async_server.hpp
+++ b/examples/http_async_server.hpp
@@ -236,8 +236,8 @@ private:
                 response<string_body> res;
                 res.result(status::not_found);
                 res.version = req_.version;
-                res.fields.insert("Server", "http_async_server");
-                res.fields.insert("Content-Type", "text/html");
+                res.insert("Server", "http_async_server");
+                res.insert("Content-Type", "text/html");
                 res.body = "The file '" + path + "' was not found";
                 prepare(res);
                 async_write(sock_, std::move(res),
@@ -250,8 +250,8 @@ private:
                 resp_type res;
                 res.result(status::ok);
                 res.version = req_.version;
-                res.fields.insert("Server", "http_async_server");
-                res.fields.insert("Content-Type", mime_type(path));
+                res.insert("Server", "http_async_server");
+                res.insert("Content-Type", mime_type(path));
                 res.body = path;
                 prepare(res);
                 async_write(sock_, std::move(res),
@@ -263,8 +263,8 @@ private:
                 response<string_body> res;
                 res.result(status::internal_server_error);
                 res.version = req_.version;
-                res.fields.insert("Server", "http_async_server");
-                res.fields.insert("Content-Type", "text/html");
+                res.insert("Server", "http_async_server");
+                res.insert("Content-Type", "text/html");
                 res.body =
                     std::string{"An internal error occurred"} + e.what();
                 prepare(res);
diff --git a/examples/http_crawl.cpp b/examples/http_crawl.cpp
index 8d945346..85fa39b8 100644
--- a/examples/http_crawl.cpp
+++ b/examples/http_crawl.cpp
@@ -40,9 +40,9 @@ int main(int, char const*[])
             req.method(verb::get);
             req.target("/");
             req.version = 11;
-            req.fields.insert("Host", host + std::string(":") +
+            req.insert("Host", host + std::string(":") +
                 boost::lexical_cast<std::string>(ep.port()));
-            req.fields.insert("User-Agent", "beast/http");
+            req.insert("User-Agent", "beast/http");
             prepare(req);
             write(sock, req);
             response<string_body> res;
diff --git a/examples/http_example.cpp b/examples/http_example.cpp
index ef268bfb..4be99e3d 100644
--- a/examples/http_example.cpp
+++ b/examples/http_example.cpp
@@ -29,9 +29,9 @@ int main()
     req.method(beast::http::verb::get);
     req.target("/");
     req.version = 11;
-    req.fields.replace("Host", host + ":" +
+    req.replace("Host", host + ":" +
         boost::lexical_cast<std::string>(sock.remote_endpoint().port()));
-    req.fields.replace("User-Agent", "Beast");
+    req.replace("User-Agent", "Beast");
     beast::http::prepare(req);
     beast::http::write(sock, req);
 
diff --git a/examples/http_sync_server.hpp b/examples/http_sync_server.hpp
index b26db6b0..7c175f0a 100644
--- a/examples/http_sync_server.hpp
+++ b/examples/http_sync_server.hpp
@@ -166,8 +166,8 @@ private:
                 response<string_body> res;
                 res.result(status::not_found);
                 res.version = req.version;
-                res.fields.insert("Server", "http_sync_server");
-                res.fields.insert("Content-Type", "text/html");
+                res.insert("Server", "http_sync_server");
+                res.insert("Content-Type", "text/html");
                 res.body = "The file '" + path + "' was not found";
                 prepare(res);
                 write(sock, res, ec);
@@ -181,8 +181,8 @@ private:
                 res.result(status::ok);
                 res.reason("OK");
                 res.version = req.version;
-                res.fields.insert("Server", "http_sync_server");
-                res.fields.insert("Content-Type", mime_type(path));
+                res.insert("Server", "http_sync_server");
+                res.insert("Content-Type", mime_type(path));
                 res.body = path;
                 prepare(res);
                 write(sock, res, ec);
@@ -195,8 +195,8 @@ private:
                 res.result(status::internal_server_error);
                 res.reason("Internal Error");
                 res.version = req.version;
-                res.fields.insert("Server", "http_sync_server");
-                res.fields.insert("Content-Type", "text/html");
+                res.insert("Server", "http_sync_server");
+                res.insert("Content-Type", "text/html");
                 res.body =
                     std::string{"An internal error occurred: "} + e.what();
                 prepare(res);
diff --git a/examples/ssl/http_ssl_example.cpp b/examples/ssl/http_ssl_example.cpp
index 7fb0bf73..0dc40d0f 100644
--- a/examples/ssl/http_ssl_example.cpp
+++ b/examples/ssl/http_ssl_example.cpp
@@ -38,9 +38,9 @@ int main()
     req.method(beast::http::verb::get);
     req.target("/");
     req.version = 11;
-    req.fields.insert("Host", host + ":" +
+    req.insert("Host", host + ":" +
         boost::lexical_cast<std::string>(sock.remote_endpoint().port()));
-    req.fields.insert("User-Agent", "Beast");
+    req.insert("User-Agent", "Beast");
     beast::http::prepare(req);
     beast::http::write(stream, req);
 
diff --git a/examples/websocket_async_echo_server.hpp b/examples/websocket_async_echo_server.hpp
index 49e8472e..75d7ddad 100644
--- a/examples/websocket_async_echo_server.hpp
+++ b/examples/websocket_async_echo_server.hpp
@@ -263,7 +263,7 @@ private:
             d.ws.async_accept_ex(
                 [](beast::websocket::response_type& res)
                 {
-                    res.fields.insert(
+                    res.insert(
                         "Server", "async_echo_server");
                 },
                 std::move(*this));
diff --git a/examples/websocket_sync_echo_server.hpp b/examples/websocket_sync_echo_server.hpp
index deb2706a..3df6ddb5 100644
--- a/examples/websocket_sync_echo_server.hpp
+++ b/examples/websocket_sync_echo_server.hpp
@@ -274,7 +274,7 @@ private:
         ws.accept_ex(
             [](beast::websocket::response_type& res)
             {
-                res.fields.insert(
+                res.insert(
                     "Server", "sync_echo_server");
             },
             ec);
diff --git a/include/beast/http/fields.hpp b/include/beast/http/fields.hpp
index 25116b92..0eb52850 100644
--- a/include/beast/http/fields.hpp
+++ b/include/beast/http/fields.hpp
@@ -268,54 +268,14 @@ public:
             boost::lexical_cast<std::string>(value));
     }
 
-#if BEAST_DOXYGEN
-private:
-#endif
-
-    string_view
-    method_impl() const
-    {
-        return (*this)[":method"];
-    }
-
-    void
-    method_impl(string_view s)
-    {
-        if(s.empty())
-            this->erase(":method");
-        else
-            this->replace(":method", s);
-    }
-
-    string_view
-    target_impl() const
-    {
-        return (*this)[":target"];
-    }
-
-    void
-    target_impl(string_view s)
-    {
-        if(s.empty())
-            this->erase(":target");
-        else
-            return this->replace(":target", s);
-    }
-
-    string_view
-    reason_impl() const
-    {
-        return (*this)[":reason"];
-    }
-
-    void
-    reason_impl(string_view s)
-    {
-        if(s.empty())
-            this->erase(":reason");
-        else
-            this->replace(":reason", s);
-    }
+protected:
+    // for header
+    string_view method_impl() const;
+    string_view target_impl() const;
+    string_view reason_impl() const;
+    void method_impl(string_view s);
+    void target_impl(string_view s);
+    void reason_impl(string_view s);
 
 private:
     struct element
diff --git a/include/beast/http/impl/fields.ipp b/include/beast/http/impl/fields.ipp
index ea265692..703f0ed3 100644
--- a/include/beast/http/impl/fields.ipp
+++ b/include/beast/http/impl/fields.ipp
@@ -26,6 +26,71 @@ basic_fields<Allocator>::
 
 //------------------------------------------------------------------------------
 
+template<class Allocator>
+inline
+string_view
+basic_fields<Allocator>::
+method_impl() const
+{
+    return (*this)[":method"];
+}
+
+template<class Allocator>
+inline
+string_view
+basic_fields<Allocator>::
+target_impl() const
+{
+    return (*this)[":target"];
+}
+
+template<class Allocator>
+inline
+string_view
+basic_fields<Allocator>::
+reason_impl() const
+{
+    return (*this)[":reason"];
+}
+
+template<class Allocator>
+inline
+void
+basic_fields<Allocator>::
+method_impl(string_view s)
+{
+    if(s.empty())
+        this->erase(":method");
+    else
+        this->replace(":method", s);
+}
+
+template<class Allocator>
+inline
+void
+basic_fields<Allocator>::
+target_impl(string_view s)
+{
+    if(s.empty())
+        this->erase(":target");
+    else
+        return this->replace(":target", s);
+}
+
+template<class Allocator>
+inline
+void
+basic_fields<Allocator>::
+reason_impl(string_view s)
+{
+    if(s.empty())
+        this->erase(":reason");
+    else
+        this->replace(":reason", s);
+}
+
+//------------------------------------------------------------------------------
+
 template<class Allocator>
 class basic_fields<Allocator>::
     const_iterator
diff --git a/include/beast/http/impl/message.ipp b/include/beast/http/impl/message.ipp
index 881b20d3..0710dd16 100644
--- a/include/beast/http/impl/message.ipp
+++ b/include/beast/http/impl/message.ipp
@@ -30,7 +30,7 @@ get_method_string() const
 {
     if(method_ != verb::unknown)
         return to_string(method_);
-    return fields.method_impl();
+    return this->method_impl();
 }
 
 template<class Fields>
@@ -43,7 +43,7 @@ set_method(verb v)
         BOOST_THROW_EXCEPTION(
             std::invalid_argument{"unknown verb"});
     method_ = v;
-    fields.method_impl({});
+    this->method_impl({});
 }
 
 template<class Fields>
@@ -54,9 +54,9 @@ set_method(string_view s)
 {
     method_ = string_to_verb(s);
     if(method_ != verb::unknown)
-        fields.method_impl({});
+        this->method_impl({});
     else
-        fields.method_impl(s);
+        this->method_impl(s);
 }
 
 template<class Fields>
@@ -65,7 +65,7 @@ string_view
 header<false, Fields>::
 get_reason() const
 {
-    auto const s = fields.reason_impl();
+    auto const s = this->reason_impl();
     if(! s.empty())
         return s;
     return obsolete_reason(result_);
@@ -74,25 +74,29 @@ get_reason() const
 template<class Fields>
 void
 swap(
-    header<true, Fields>& m1,
-    header<true, Fields>& m2)
+    header<true, Fields>& h1,
+    header<true, Fields>& h2)
 {
     using std::swap;
-    swap(m1.version, m2.version);
-    swap(m1.fields, m2.fields);
-    swap(m1.method_, m2.method_);
+    swap(
+        static_cast<Fields&>(h1),
+        static_cast<Fields&>(h2));
+    swap(h1.version, h2.version);
+    swap(h1.method_, h2.method_);
 }
 
 template<class Fields>
 void
 swap(
-    header<false, Fields>& a,
-    header<false, Fields>& b)
+    header<false, Fields>& h1,
+    header<false, Fields>& h2)
 {
     using std::swap;
-    swap(a.version, b.version);
-    swap(a.fields, b.fields);
-    swap(a.result_, b.result_);
+    swap(
+        static_cast<Fields&>(h1),
+        static_cast<Fields&>(h2));
+    swap(h1.version, h2.version);
+    swap(h1.result_, h2.result_);
 }
 
 template<bool isRequest, class Body, class Fields>
@@ -113,11 +117,11 @@ is_keep_alive(header<isRequest, Fields> const& msg)
     BOOST_ASSERT(msg.version == 10 || msg.version == 11);
     if(msg.version == 11)
     {
-        if(token_list{msg.fields["Connection"]}.exists("close"))
+        if(token_list{msg["Connection"]}.exists("close"))
             return false;
         return true;
     }
-    if(token_list{msg.fields["Connection"]}.exists("keep-alive"))
+    if(token_list{msg["Connection"]}.exists("keep-alive"))
         return true;
     return false;
 }
@@ -129,7 +133,7 @@ is_upgrade(header<isRequest, Fields> const& msg)
     BOOST_ASSERT(msg.version == 10 || msg.version == 11);
     if(msg.version == 10)
         return false;
-    if(token_list{msg.fields["Connection"]}.exists("upgrade"))
+    if(token_list{msg["Connection"]}.exists("upgrade"))
         return true;
     return false;
 }
@@ -219,15 +223,15 @@ prepare(message<isRequest, Body, Fields>& msg,
     detail::prepare_options(pi, msg,
         std::forward<Options>(options)...);
 
-    if(msg.fields.exists("Connection"))
+    if(msg.exists("Connection"))
         BOOST_THROW_EXCEPTION(std::invalid_argument{
             "prepare called with Connection field set"});
 
-    if(msg.fields.exists("Content-Length"))
+    if(msg.exists("Content-Length"))
         BOOST_THROW_EXCEPTION(std::invalid_argument{
             "prepare called with Content-Length field set"});
 
-    if(token_list{msg.fields["Transfer-Encoding"]}.exists("chunked"))
+    if(token_list{msg["Transfer-Encoding"]}.exists("chunked"))
         BOOST_THROW_EXCEPTION(std::invalid_argument{
             "prepare called with Transfer-Encoding: chunked set"});
 
@@ -245,7 +249,7 @@ prepare(message<isRequest, Body, Fields>& msg,
                     if(*pi.content_length > 0 ||
                         msg.method() == verb::post)
                     {
-                        msg.fields.insert(
+                        msg.insert(
                             "Content-Length", *pi.content_length);
                     }
                 }
@@ -258,7 +262,7 @@ prepare(message<isRequest, Body, Fields>& msg,
                         msg.result() != status::no_content &&
                         msg.result() != status::not_modified)
                     {
-                        msg.fields.insert(
+                        msg.insert(
                             "Content-Length", *pi.content_length);
                     }
                 }
@@ -267,39 +271,39 @@ prepare(message<isRequest, Body, Fields>& msg,
         }
         else if(msg.version >= 11)
         {
-            msg.fields.insert("Transfer-Encoding", "chunked");
+            msg.insert("Transfer-Encoding", "chunked");
         }
     }
 
     auto const content_length =
-        msg.fields.exists("Content-Length");
+        msg.exists("Content-Length");
 
     if(pi.connection_value)
     {
         switch(*pi.connection_value)
         {
         case connection::upgrade:
-            msg.fields.insert("Connection", "upgrade");
+            msg.insert("Connection", "upgrade");
             break;
 
         case connection::keep_alive:
             if(msg.version < 11)
             {
                 if(content_length)
-                    msg.fields.insert("Connection", "keep-alive");
+                    msg.insert("Connection", "keep-alive");
             }
             break;
 
         case connection::close:
             if(msg.version >= 11)
-                msg.fields.insert("Connection", "close");
+                msg.insert("Connection", "close");
             break;
         }
     }
 
     // rfc7230 6.7.
     if(msg.version < 11 && token_list{
-            msg.fields["Connection"]}.exists("upgrade"))
+            msg["Connection"]}.exists("upgrade"))
         BOOST_THROW_EXCEPTION(std::invalid_argument{
             "invalid version for Connection: upgrade"});
 }
diff --git a/include/beast/http/impl/serializer.ipp b/include/beast/http/impl/serializer.ipp
index 4a9209b8..3338d2ce 100644
--- a/include/beast/http/impl/serializer.ipp
+++ b/include/beast/http/impl/serializer.ipp
@@ -94,12 +94,12 @@ get(error_code& ec, Visit&& visit)
     case do_construct:
     {
         chunked_ = token_list{
-            m_.fields["Transfer-Encoding"]}.exists("chunked");
-        close_ = token_list{m_.fields["Connection"]}.exists("close") ||
-            (m_.version < 11 && ! m_.fields.exists("Content-Length"));
+            m_["Transfer-Encoding"]}.exists("chunked");
+        close_ = token_list{m_["Connection"]}.exists("close") ||
+            (m_.version < 11 && ! m_.exists("Content-Length"));
         auto os = ostream(b_);
         detail::write_start_line(os, m_);
-        detail::write_fields(os, m_.fields);
+        detail::write_fields(os, m_);
         os << "\r\n";
         if(chunked_)
             goto go_init_c;
diff --git a/include/beast/http/impl/write.ipp b/include/beast/http/impl/write.ipp
index 1f5f58a5..a8ecd7ed 100644
--- a/include/beast/http/impl/write.ipp
+++ b/include/beast/http/impl/write.ipp
@@ -828,7 +828,7 @@ operator<<(std::ostream& os,
     header<isRequest, Fields> const& msg)
 {
     detail::write_start_line(os, msg);
-    detail::write_fields(os, msg.fields);
+    detail::write_fields(os, msg);
     os << "\r\n";
     return os;
 }
diff --git a/include/beast/http/message.hpp b/include/beast/http/message.hpp
index a48ffcb0..33f02bc0 100644
--- a/include/beast/http/message.hpp
+++ b/include/beast/http/message.hpp
@@ -45,7 +45,7 @@ template<bool isRequest, class Fields = fields>
 struct header;
 
 template<class Fields>
-struct header<true, Fields>
+struct header<true, Fields> : Fields
 #endif
 {
     /// Indicates if the header is a request or response.
@@ -59,6 +59,17 @@ struct header<true, Fields>
     /// The type representing the fields.
     using fields_type = Fields;
 
+    /** The HTTP-version.
+
+        This holds both the major and minor version numbers,
+        using these formulas:
+        @code
+            int major = version / 10;
+            int minor = version % 10;
+        @endcode
+    */
+    int version;
+
     /// Default constructor
     header() = default;
 
@@ -96,25 +107,11 @@ struct header<true, Fields>
                     header>::value>::type>
     explicit
     header(Arg1&& arg1, ArgN&&... argn)
-        : fields(std::forward<Arg1>(arg1),
+        : Fields(std::forward<Arg1>(arg1),
             std::forward<ArgN>(argn)...)
     {
     }
 
-    /** The HTTP-version.
-
-        This holds both the major and minor version numbers,
-        using these formulas:
-        @code
-            int major = version / 10;
-            int minor = version % 10;
-        @endcode
-    */
-    int version;
-
-    /// The HTTP field values.
-    fields_type fields;
-
     /** Return the request-method verb.
 
         If the request-method is not one of the recognized verbs,
@@ -181,7 +178,7 @@ struct header<true, Fields>
     string_view
     target() const
     {
-        return fields.target_impl();
+        return this->target_impl();
     }
 
     /** Set the request-target string.
@@ -193,7 +190,7 @@ struct header<true, Fields>
     void
     target(string_view s)
     {
-        fields.target_impl(s);
+        this->target_impl(s);
     }
 
 private:
@@ -230,7 +227,7 @@ private:
     @li Invoke algorithms which operate on the header only.
 */
 template<class Fields>
-struct header<false, Fields>
+struct header<false, Fields> : Fields
 {
     /// Indicates if the header is a request or response.
     static bool constexpr is_request = false;
@@ -249,9 +246,6 @@ struct header<false, Fields>
     */
     int version;
 
-    /// The HTTP field values.
-    fields_type fields;
-
     /// Default constructor.
     header() = default;
 
@@ -283,7 +277,7 @@ struct header<false, Fields>
                     header>::value>::type>
     explicit
     header(Arg1&& arg1, ArgN&&... argn)
-        : fields(std::forward<Arg1>(arg1),
+        : Fields(std::forward<Arg1>(arg1),
             std::forward<ArgN>(argn)...)
     {
     }
@@ -379,7 +373,7 @@ struct header<false, Fields>
     void
     reason(string_view s)
     {
-        fields.reason_impl(s);
+        this->reason_impl(s);
     }
    
 private:
diff --git a/include/beast/http/parser.hpp b/include/beast/http/parser.hpp
index b1118793..9019a5eb 100644
--- a/include/beast/http/parser.hpp
+++ b/include/beast/http/parser.hpp
@@ -208,7 +208,7 @@ private:
         string_view value,
             error_code&)
     {
-        m_.fields.insert(name, value);
+        m_.insert(name, value);
     }
 
     void
diff --git a/include/beast/websocket/impl/accept.ipp b/include/beast/websocket/impl/accept.ipp
index 901b16ce..5381e091 100644
--- a/include/beast/websocket/impl/accept.ipp
+++ b/include/beast/websocket/impl/accept.ipp
@@ -153,8 +153,7 @@ operator()(error_code ec, bool again)
                 ec = error::handshake_failed;
             if(! ec)
             {
-                pmd_read(
-                    d.ws.pmd_config_, d.res.fields);
+                pmd_read(d.ws.pmd_config_, d.res);
                 d.ws.open(detail::role_type::server);
             }
             break;
diff --git a/include/beast/websocket/impl/handshake.ipp b/include/beast/websocket/impl/handshake.ipp
index cae20f99..3dfad407 100644
--- a/include/beast/websocket/impl/handshake.ipp
+++ b/include/beast/websocket/impl/handshake.ipp
@@ -132,8 +132,7 @@ operator()(error_code ec, bool again)
             // VFALCO Do we need the ability to move
             //        a message on the async_write?
             //
-            pmd_read(
-                d.ws.pmd_config_, d.req.fields);
+            pmd_read(d.ws.pmd_config_, d.req);
             http::async_write(d.ws.stream_,
                 d.req, std::move(*this));
             // TODO We don't need d.req now. Figure
diff --git a/include/beast/websocket/impl/rfc6455.ipp b/include/beast/websocket/impl/rfc6455.ipp
index d8153785..582d2dee 100644
--- a/include/beast/websocket/impl/rfc6455.ipp
+++ b/include/beast/websocket/impl/rfc6455.ipp
@@ -23,9 +23,9 @@ is_upgrade(http::header<true, Fields> const& req)
         return false;
     if(! http::is_upgrade(req))
         return false;
-    if(! http::token_list{req.fields["Upgrade"]}.exists("websocket"))
+    if(! http::token_list{req["Upgrade"]}.exists("websocket"))
         return false;
-    if(! req.fields.exists("Sec-WebSocket-Version"))
+    if(! req.exists("Sec-WebSocket-Version"))
         return false;
     return true;
 }
diff --git a/include/beast/websocket/impl/stream.ipp b/include/beast/websocket/impl/stream.ipp
index aebaef09..75adb35f 100644
--- a/include/beast/websocket/impl/stream.ipp
+++ b/include/beast/websocket/impl/stream.ipp
@@ -117,7 +117,7 @@ do_accept(http::header<true, Fields> const& req,
         //             teardown if Connection: close.
         return;
     }
-    pmd_read(pmd_config_, req.fields);
+    pmd_read(pmd_config_, req);
     open(detail::role_type::server);
 }
 
@@ -137,7 +137,7 @@ do_handshake(response_type* res_p,
     {
         auto const req = build_request(
             key, host, target, decorator);
-        pmd_read(pmd_config_, req.fields);
+        pmd_read(pmd_config_, req);
         http::write(stream_, req, ec);
     }
     if(ec)
@@ -163,12 +163,12 @@ build_request(detail::sec_ws_key_type& key,
     req.target(target);
     req.version = 11;
     req.method(http::verb::get);
-    req.fields.insert("Host", host);
-    req.fields.insert("Upgrade", "websocket");
-    req.fields.insert("Connection", "upgrade");
+    req.insert("Host", host);
+    req.insert("Upgrade", "websocket");
+    req.insert("Connection", "upgrade");
     detail::make_sec_ws_key(key, maskgen_);
-    req.fields.insert("Sec-WebSocket-Key", key);
-    req.fields.insert("Sec-WebSocket-Version", "13");
+    req.insert("Sec-WebSocket-Key", key);
+    req.insert("Sec-WebSocket-Version", "13");
     if(pmd_opts_.client_enable)
     {
         detail::pmd_offer config;
@@ -181,14 +181,13 @@ build_request(detail::sec_ws_key_type& key,
             pmd_opts_.server_no_context_takeover;
         config.client_no_context_takeover =
             pmd_opts_.client_no_context_takeover;
-        detail::pmd_write(
-            req.fields, config);
+        detail::pmd_write(req, config);
     }
     decorator(req);
-    if(! req.fields.exists("User-Agent"))
+    if(! req.exists("User-Agent"))
     {
         static_string<20> s(BEAST_VERSION_STRING);
-        req.fields.insert("User-Agent", s);
+        req.insert("User-Agent", s);
     }
     return req;
 }
@@ -204,10 +203,10 @@ build_response(http::header<true, Fields> const& req,
         [&decorator](response_type& res)
         {
             decorator(res);
-            if(! res.fields.exists("Server"))
+            if(! res.exists("Server"))
             {
                 static_string<20> s(BEAST_VERSION_STRING);
-                res.fields.insert("Server", s);
+                res.insert("Server", s);
             }
         };
     auto err =
@@ -227,18 +226,18 @@ build_response(http::header<true, Fields> const& req,
         return err("Wrong method");
     if(! is_upgrade(req))
         return err("Expected Upgrade request");
-    if(! req.fields.exists("Host"))
+    if(! req.exists("Host"))
         return err("Missing Host");
-    if(! req.fields.exists("Sec-WebSocket-Key"))
+    if(! req.exists("Sec-WebSocket-Key"))
         return err("Missing Sec-WebSocket-Key");
-    if(! http::token_list{req.fields["Upgrade"]}.exists("websocket"))
+    if(! http::token_list{req["Upgrade"]}.exists("websocket"))
         return err("Missing websocket Upgrade token");
-    auto const key = req.fields["Sec-WebSocket-Key"];
+    auto const key = req["Sec-WebSocket-Key"];
     if(key.size() > detail::sec_ws_key_type::max_size_n)
         return err("Invalid Sec-WebSocket-Key");
     {
         auto const version =
-            req.fields["Sec-WebSocket-Version"];
+            req["Sec-WebSocket-Version"];
         if(version.empty())
             return err("Missing Sec-WebSocket-Version");
         if(version != "13")
@@ -246,7 +245,7 @@ build_response(http::header<true, Fields> const& req,
             response_type res;
             res.result(http::status::upgrade_required);
             res.version = req.version;
-            res.fields.insert("Sec-WebSocket-Version", "13");
+            res.insert("Sec-WebSocket-Version", "13");
             prepare(res);
             decorate(res);
             return res;
@@ -257,18 +256,17 @@ build_response(http::header<true, Fields> const& req,
     {
         detail::pmd_offer offer;
         detail::pmd_offer unused;
-        pmd_read(offer, req.fields);
-        pmd_negotiate(
-            res.fields, unused, offer, pmd_opts_);
+        pmd_read(offer, req);
+        pmd_negotiate(res, unused, offer, pmd_opts_);
     }
     res.result(http::status::switching_protocols);
     res.version = req.version;
-    res.fields.insert("Upgrade", "websocket");
-    res.fields.insert("Connection", "upgrade");
+    res.insert("Upgrade", "websocket");
+    res.insert("Connection", "upgrade");
     {
         detail::sec_ws_accept_type accept;
         detail::make_sec_ws_accept(accept, key);
-        res.fields.insert("Sec-WebSocket-Accept", accept);
+        res.insert("Sec-WebSocket-Accept", accept);
     }
     decorate(res);
     return res;
@@ -288,14 +286,14 @@ do_response(http::header<false> const& res,
             return false;
         if(! is_upgrade(res))
             return false;
-        if(! http::token_list{res.fields["Upgrade"]}.exists("websocket"))
+        if(! http::token_list{res["Upgrade"]}.exists("websocket"))
             return false;
-        if(! res.fields.exists("Sec-WebSocket-Accept"))
+        if(! res.exists("Sec-WebSocket-Accept"))
             return false;
         detail::sec_ws_accept_type accept;
         detail::make_sec_ws_accept(accept, key);
         if(accept.compare(
-                res.fields["Sec-WebSocket-Accept"]) != 0)
+                res["Sec-WebSocket-Accept"]) != 0)
             return false;
         return true;
     }();
@@ -305,7 +303,7 @@ do_response(http::header<false> const& res,
         return;
     }
     detail::pmd_offer offer;
-    pmd_read(offer, res.fields);
+    pmd_read(offer, res);
     // VFALCO see if offer satisfies pmd_config_,
     //        return an error if not.
     pmd_config_ = offer; // overwrite for now
diff --git a/include/beast/websocket/stream.hpp b/include/beast/websocket/stream.hpp
index daf357e4..9c8367f5 100644
--- a/include/beast/websocket/stream.hpp
+++ b/include/beast/websocket/stream.hpp
@@ -1563,7 +1563,7 @@ public:
             ws.handshake("localhost", "/",
                 [](request_type& req)
                 {
-                    req.fields.insert("User-Agent", "Beast");
+                    req.insert("User-Agent", "Beast");
                 });
         }
         catch(...)
@@ -1625,7 +1625,7 @@ public:
             ws.handshake(res, "localhost", "/",
                 [](request_type& req)
                 {
-                    req.fields.insert("User-Agent", "Beast");
+                    req.insert("User-Agent", "Beast");
                 });
         }
         catch(...)
@@ -1771,7 +1771,7 @@ public:
         ws.handshake("localhost", "/",
             [](request_type& req)
             {
-                req.fields.insert("User-Agent", "Beast");
+                req.insert("User-Agent", "Beast");
             },
             ec);
         if(ec)
@@ -1833,7 +1833,7 @@ public:
         ws.handshake(res, "localhost", "/",
             [](request_type& req)
             {
-                req.fields.insert("User-Agent", "Beast");
+                req.insert("User-Agent", "Beast");
             },
             ec);
         if(ec)
diff --git a/test/http/doc_http_samples.cpp b/test/http/doc_http_samples.cpp
index 2280b964..0f557494 100644
--- a/test/http/doc_http_samples.cpp
+++ b/test/http/doc_http_samples.cpp
@@ -66,11 +66,11 @@ public:
             [&](yield_context)
             {
                 flat_buffer buffer;
-                request<string_body, fields> req;
+                request<string_body> req;
                 req.version = 11;
                 req.method("POST");
                 req.target("/");
-                req.fields.insert("User-Agent", "test");
+                req.insert("User-Agent", "test");
                 req.body = "Hello, world!";
                 prepare(req);
 
@@ -99,11 +99,11 @@ public:
     void
     doRelay()
     {
-        request<string_body, fields> req;
+        request<string_body> req;
         req.version = 11;
         req.method("POST");
         req.target("/");
-        req.fields.insert("User-Agent", "test");
+        req.insert("User-Agent", "test");
         req.body = "Hello, world!";
         prepare(req);
 
@@ -121,8 +121,8 @@ public:
         relay<true>(upstream.client, downstream.server, buffer, ec,
             [&](header<true, fields>& h, error_code& ec)
             {
-                h.fields.erase("Content-Length");
-                h.fields.replace("Transfer-Encoding", "chunked");
+                h.erase("Content-Length");
+                h.replace("Transfer-Encoding", "chunked");
             });
         BEAST_EXPECTS(! ec, ec.message());
         BEAST_EXPECT(equal_body<true>(
@@ -155,7 +155,7 @@ public:
         req.version = 11;
         req.method(verb::get);
         req.target("/");
-        req.fields.insert("User-Agent", "test");
+        req.insert("User-Agent", "test");
         error_code ec;
         write_ostream(os, req, ec);
         BEAST_EXPECTS(! ec, ec.message());
diff --git a/test/http/fields.cpp b/test/http/fields.cpp
index c34b1bf3..0f204006 100644
--- a/test/http/fields.cpp
+++ b/test/http/fields.cpp
@@ -99,24 +99,11 @@ public:
         BEAST_EXPECT(size(f) == 2);
     }
 
-    void
-    testMethodString()
-    {
-        f_t f;
-        f.method_impl("CRY");
-        BEAST_EXPECTS(f.method_impl() == "CRY", f.method_impl());
-        f.method_impl("PUT");
-        BEAST_EXPECTS(f.method_impl() == "PUT", f.method_impl());
-        f.method_impl({});
-        BEAST_EXPECTS(f.method_impl().empty(), f.method_impl());
-    }
-
     void run() override
     {
         testHeaders();
         testRFC2616();
         testErase();
-        testMethodString();
     }
 };
 
diff --git a/test/http/message.cpp b/test/http/message.cpp
index e006f31c..23a0bb5e 100644
--- a/test/http/message.cpp
+++ b/test/http/message.cpp
@@ -118,14 +118,14 @@ public:
             h.insert("User-Agent", "test");
             message<true, one_arg_body, fields> m{Arg1{}, h};
             BEAST_EXPECT(h["User-Agent"] == "test");
-            BEAST_EXPECT(m.fields["User-Agent"] == "test");
+            BEAST_EXPECT(m["User-Agent"] == "test");
         }
         {
             fields h;
             h.insert("User-Agent", "test");
             message<true, one_arg_body, fields> m{Arg1{}, std::move(h)};
             BEAST_EXPECT(! h.exists("User-Agent"));
-            BEAST_EXPECT(m.fields["User-Agent"] == "test");
+            BEAST_EXPECT(m["User-Agent"] == "test");
         }
 
         // swap
@@ -133,7 +133,7 @@ public:
         message<true, string_body, fields> m2;
         m1.target("u");
         m1.body = "1";
-        m1.fields.insert("h", "v");
+        m1.insert("h", "v");
         m2.method("G");
         m2.body = "2";
         swap(m1, m2);
@@ -143,8 +143,8 @@ public:
         BEAST_EXPECT(m2.target() == "u");
         BEAST_EXPECT(m1.body == "2");
         BEAST_EXPECT(m2.body == "1");
-        BEAST_EXPECT(! m1.fields.exists("h"));
-        BEAST_EXPECT(m2.fields.exists("h"));
+        BEAST_EXPECT(! m1.exists("h"));
+        BEAST_EXPECT(m2.exists("h"));
     }
 
     struct MoveFields : fields
@@ -187,10 +187,10 @@ public:
             MoveFields h;
             header<true, MoveFields> r{std::move(h)};
             BEAST_EXPECT(h.moved_from);
-            BEAST_EXPECT(r.fields.moved_to);
+            BEAST_EXPECT(r.moved_to);
             request<string_body, MoveFields> m{std::move(r)};
-            BEAST_EXPECT(r.fields.moved_from);
-            BEAST_EXPECT(m.fields.moved_to);
+            BEAST_EXPECT(r.moved_from);
+            BEAST_EXPECT(m.moved_to);
         }
     }
 
@@ -202,12 +202,12 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 11;
-            m.fields.insert("Upgrade", "test");
+            m.insert("Upgrade", "test");
             BEAST_EXPECT(! is_upgrade(m));
 
             prepare(m, connection::upgrade);
             BEAST_EXPECT(is_upgrade(m));
-            BEAST_EXPECT(m.fields["Connection"] == "upgrade");
+            BEAST_EXPECT(m["Connection"] == "upgrade");
 
             m.version = 10;
             BEAST_EXPECT(! is_upgrade(m));
@@ -220,7 +220,7 @@ public:
         request<string_body> m;
         m.version = 10;
         BEAST_EXPECT(! is_upgrade(m));
-        m.fields.insert("Transfer-Encoding", "chunked");
+        m.insert("Transfer-Encoding", "chunked");
         try
         {
             prepare(m);
@@ -229,8 +229,8 @@ public:
         catch(std::exception const&)
         {
         }
-        m.fields.erase("Transfer-Encoding");
-        m.fields.insert("Content-Length", "0");
+        m.erase("Transfer-Encoding");
+        m.insert("Content-Length", "0");
         try
         {
             prepare(m);
@@ -240,8 +240,8 @@ public:
         {
             pass();
         }
-        m.fields.erase("Content-Length");
-        m.fields.insert("Connection", "keep-alive");
+        m.erase("Content-Length");
+        m.insert("Connection", "keep-alive");
         try
         {
             prepare(m);
@@ -252,8 +252,8 @@ public:
             pass();
         }
         m.version = 11;
-        m.fields.erase("Connection");
-        m.fields.insert("Connection", "close");
+        m.erase("Connection");
+        m.insert("Connection", "close");
         BEAST_EXPECT(! is_keep_alive(m));
     }
 
@@ -265,7 +265,7 @@ public:
         m1.result(status::ok);
         m1.version = 10;
         m1.body = "1";
-        m1.fields.insert("h", "v");
+        m1.insert("h", "v");
         m2.result(status::not_found);
         m2.body = "2";
         m2.version = 11;
@@ -280,8 +280,8 @@ public:
         BEAST_EXPECT(m2.version == 10);
         BEAST_EXPECT(m1.body == "2");
         BEAST_EXPECT(m2.body == "1");
-        BEAST_EXPECT(! m1.fields.exists("h"));
-        BEAST_EXPECT(m2.fields.exists("h"));
+        BEAST_EXPECT(! m1.exists("h"));
+        BEAST_EXPECT(m2.exists("h"));
     }
 
     void
diff --git a/test/http/parser.cpp b/test/http/parser.cpp
index 32cdc076..6a92e46a 100644
--- a/test/http/parser.cpp
+++ b/test/http/parser.cpp
@@ -133,7 +133,7 @@ public:
                 BEAST_EXPECT(m.version == 10);
                 BEAST_EXPECT(m.result() == status::ok);
                 BEAST_EXPECT(m.reason() == "OK");
-                BEAST_EXPECT(m.fields["Server"] == "test");
+                BEAST_EXPECT(m["Server"] == "test");
                 BEAST_EXPECT(m.body == "Hello, world!");
             }
         );
@@ -160,10 +160,10 @@ public:
                 BEAST_EXPECT(m.version == 11);
                 BEAST_EXPECT(m.result() == status::ok);
                 BEAST_EXPECT(m.reason() == "OK");
-                BEAST_EXPECT(m.fields["Server"] == "test");
-                BEAST_EXPECT(m.fields["Transfer-Encoding"] == "chunked");
-                BEAST_EXPECT(m.fields["Expires"] == "never");
-                BEAST_EXPECT(m.fields["MD5-Fingerprint"] == "-");
+                BEAST_EXPECT(m["Server"] == "test");
+                BEAST_EXPECT(m["Transfer-Encoding"] == "chunked");
+                BEAST_EXPECT(m["Expires"] == "never");
+                BEAST_EXPECT(m["MD5-Fingerprint"] == "-");
                 BEAST_EXPECT(m.body == "*****--");
             }
         );
@@ -202,7 +202,7 @@ public:
             [&](parser_type<true> const& p)
             {
                 auto const& m = p.get();
-                BEAST_EXPECT(m.fields["X"] == "x");
+                BEAST_EXPECT(m["X"] == "x");
             }
         );
 
@@ -226,7 +226,7 @@ public:
             BEAST_EXPECT(m.method() == verb::get);
             BEAST_EXPECT(m.target() == "/");
             BEAST_EXPECT(m.version == 11);
-            BEAST_EXPECT(m.fields["User-Agent"] == "test");
+            BEAST_EXPECT(m["User-Agent"] == "test");
             BEAST_EXPECT(m.body == "*");
         }
         {
diff --git a/test/http/write.cpp b/test/http/write.cpp
index a603cfd8..a9a7441e 100644
--- a/test/http/write.cpp
+++ b/test/http/write.cpp
@@ -294,8 +294,8 @@ public:
             m.version = 10;
             m.result(status::ok);
             m.reason("OK");
-            m.fields.insert("Server", "test");
-            m.fields.insert("Content-Length", "5");
+            m.insert("Server", "test");
+            m.insert("Content-Length", "5");
             m.body = "*****";
             error_code ec;
             test::string_ostream ss{ios_};
@@ -313,8 +313,8 @@ public:
             m.version = 11;
             m.result(status::ok);
             m.reason("OK");
-            m.fields.insert("Server", "test");
-            m.fields.insert("Transfer-Encoding", "chunked");
+            m.insert("Server", "test");
+            m.insert("Transfer-Encoding", "chunked");
             m.body = "*****";
             error_code ec;
             test::string_ostream ss(ios_);
@@ -346,8 +346,8 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
-            m.fields.insert("Content-Length", "5");
+            m.insert("User-Agent", "test");
+            m.insert("Content-Length", "5");
             m.body = "*****";
             try
             {
@@ -377,8 +377,8 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
-            m.fields.insert("Transfer-Encoding", "chunked");
+            m.insert("User-Agent", "test");
+            m.insert("Transfer-Encoding", "chunked");
             m.body = "*****";
             error_code ec;
             write(fs, m, ec);
@@ -410,8 +410,8 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
-            m.fields.insert("Transfer-Encoding", "chunked");
+            m.insert("User-Agent", "test");
+            m.insert("Transfer-Encoding", "chunked");
             m.body = "*****";
             error_code ec;
             async_write(fs, m, do_yield[ec]);
@@ -443,8 +443,8 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
-            m.fields.insert("Content-Length", "5");
+            m.insert("User-Agent", "test");
+            m.insert("Content-Length", "5");
             m.body = "*****";
             error_code ec;
             write(fs, m, ec);
@@ -471,8 +471,8 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
-            m.fields.insert("Content-Length", "5");
+            m.insert("User-Agent", "test");
+            m.insert("Content-Length", "5");
             m.body = "*****";
             error_code ec;
             async_write(fs, m, do_yield[ec]);
@@ -500,7 +500,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             m.body = "*";
             prepare(m);
             BEAST_EXPECT(str(m) ==
@@ -517,7 +517,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             m.body = "*";
             prepare(m, connection::keep_alive);
             BEAST_EXPECT(str(m) ==
@@ -535,7 +535,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             m.body = "*";
             try
             {
@@ -553,7 +553,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 10;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             m.body = "*";
             prepare(m);
             test::string_ostream ss(ios_);
@@ -573,7 +573,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 11;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             m.body = "*";
             prepare(m);
             BEAST_EXPECT(str(m) ==
@@ -590,7 +590,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 11;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             m.body = "*";
             prepare(m, connection::close);
             test::string_ostream ss(ios_);
@@ -612,7 +612,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 11;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             prepare(m, connection::upgrade);
             BEAST_EXPECT(str(m) ==
                 "GET / HTTP/1.1\r\n"
@@ -627,7 +627,7 @@ public:
             m.method(verb::get);
             m.target("/");
             m.version = 11;
-            m.fields.insert("User-Agent", "test");
+            m.insert("User-Agent", "test");
             m.body = "*";
             prepare(m);
             test::string_ostream ss(ios_);
@@ -652,7 +652,7 @@ public:
         m.method(verb::get);
         m.target("/");
         m.version = 11;
-        m.fields.insert("User-Agent", "test");
+        m.insert("User-Agent", "test");
         m.body = "*";
         BEAST_EXPECT(boost::lexical_cast<std::string>(m) ==
             "GET / HTTP/1.1\r\nUser-Agent: test\r\n\r\n*");
@@ -684,7 +684,7 @@ public:
             m.method(verb::get);
             m.version = 11;
             m.target("/");
-            m.fields.insert("Content-Length", 5);
+            m.insert("Content-Length", 5);
             m.body = "*****";
             async_write(os, m, handler{});
             BEAST_EXPECT(handler::count() > 0);
@@ -706,7 +706,7 @@ public:
                 m.method(verb::get);
                 m.version = 11;
                 m.target("/");
-                m.fields.insert("Content-Length", 5);
+                m.insert("Content-Length", 5);
                 m.body = "*****";
                 async_write(is, m, handler{});
                 BEAST_EXPECT(handler::count() > 0);
@@ -788,7 +788,7 @@ public:
         m0.version = 11;
         m0.result(status::ok);
         m0.reason("OK");
-        m0.fields.insert("Server", "test");
+        m0.insert("Server", "test");
         m0.body.s = "Hello, world!\n";
 
         {
@@ -845,7 +845,7 @@ public:
             }
         }
         {
-            m0.fields.insert("Transfer-Encoding", "chunked");
+            m0.insert("Transfer-Encoding", "chunked");
             {
                 auto m = m0;
                 error_code ec;
diff --git a/test/websocket/rfc6455.cpp b/test/websocket/rfc6455.cpp
index c2a37545..169ba810 100644
--- a/test/websocket/rfc6455.cpp
+++ b/test/websocket/rfc6455.cpp
@@ -28,11 +28,11 @@ public:
         req.target("/");
         BEAST_EXPECT(! is_upgrade(req));
         req.method(http::verb::get);
-        req.fields.insert("Connection", "upgrade");
+        req.insert("Connection", "upgrade");
         BEAST_EXPECT(! is_upgrade(req));
-        req.fields.insert("Upgrade", "websocket");
+        req.insert("Upgrade", "websocket");
         BEAST_EXPECT(! is_upgrade(req));
-        req.fields.insert("Sec-WebSocket-Version", "13");
+        req.insert("Sec-WebSocket-Version", "13");
         BEAST_EXPECT(is_upgrade(req));
     }
 
diff --git a/test/websocket/ssl/websocket_async_ssl_echo_server.hpp b/test/websocket/ssl/websocket_async_ssl_echo_server.hpp
index 919571ad..6a2f0b50 100644
--- a/test/websocket/ssl/websocket_async_ssl_echo_server.hpp
+++ b/test/websocket/ssl/websocket_async_ssl_echo_server.hpp
@@ -225,7 +225,7 @@ private:
                 d.ws.async_accept_ex(
                     [](beast::websocket::response_type& res)
                     {
-                        res.fields.insert(
+                        res.insert(
                             "Server", "async_ssl_echo_server");
                     },
                     d.strand.wrap(std::move(*this)));
diff --git a/test/websocket/stream.cpp b/test/websocket/stream.cpp
index 50d23be6..a98e08cb 100644
--- a/test/websocket/stream.cpp
+++ b/test/websocket/stream.cpp
@@ -707,11 +707,11 @@ public:
                     req.method(http::verb::get);
                     req.target("/");
                     req.version = 11;
-                    req.fields.insert("Host", "localhost");
-                    req.fields.insert("Upgrade", "websocket");
-                    req.fields.insert("Connection", "upgrade");
-                    req.fields.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
-                    req.fields.insert("Sec-WebSocket-Version", "13");
+                    req.insert("Host", "localhost");
+                    req.insert("Upgrade", "websocket");
+                    req.insert("Connection", "upgrade");
+                    req.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
+                    req.insert("Sec-WebSocket-Version", "13");
                     stream<test::fail_stream<
                         test::string_ostream>> ws{fc, ios_};
                     c.accept(ws, req);
@@ -721,11 +721,11 @@ public:
                     req.method(http::verb::get);
                     req.target("/");
                     req.version = 11;
-                    req.fields.insert("Host", "localhost");
-                    req.fields.insert("Upgrade", "websocket");
-                    req.fields.insert("Connection", "upgrade");
-                    req.fields.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
-                    req.fields.insert("Sec-WebSocket-Version", "13");
+                    req.insert("Host", "localhost");
+                    req.insert("Upgrade", "websocket");
+                    req.insert("Connection", "upgrade");
+                    req.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
+                    req.insert("Sec-WebSocket-Version", "13");
                     stream<test::fail_stream<
                         test::string_ostream>> ws{fc, ios_};
                     bool called = false;
@@ -739,11 +739,11 @@ public:
                     req.method(http::verb::get);
                     req.target("/");
                     req.version = 11;
-                    req.fields.insert("Host", "localhost");
-                    req.fields.insert("Upgrade", "websocket");
-                    req.fields.insert("Connection", "upgrade");
-                    req.fields.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
-                    req.fields.insert("Sec-WebSocket-Version", "13");
+                    req.insert("Host", "localhost");
+                    req.insert("Upgrade", "websocket");
+                    req.insert("Connection", "upgrade");
+                    req.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
+                    req.insert("Sec-WebSocket-Version", "13");
                     stream<test::fail_stream<
                         test::string_ostream>> ws{fc, ios_};
                     c.accept(ws, req,
@@ -766,11 +766,11 @@ public:
                     req.method(http::verb::get);
                     req.target("/");
                     req.version = 11;
-                    req.fields.insert("Host", "localhost");
-                    req.fields.insert("Upgrade", "websocket");
-                    req.fields.insert("Connection", "upgrade");
-                    req.fields.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
-                    req.fields.insert("Sec-WebSocket-Version", "13");
+                    req.insert("Host", "localhost");
+                    req.insert("Upgrade", "websocket");
+                    req.insert("Connection", "upgrade");
+                    req.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
+                    req.insert("Sec-WebSocket-Version", "13");
                     stream<test::fail_stream<
                         test::string_ostream>> ws{fc, ios_};
                     bool called = false;
@@ -797,11 +797,11 @@ public:
                     req.method(http::verb::get);
                     req.target("/");
                     req.version = 11;
-                    req.fields.insert("Host", "localhost");
-                    req.fields.insert("Upgrade", "websocket");
-                    req.fields.insert("Connection", "upgrade");
-                    req.fields.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
-                    req.fields.insert("Sec-WebSocket-Version", "13");
+                    req.insert("Host", "localhost");
+                    req.insert("Upgrade", "websocket");
+                    req.insert("Connection", "upgrade");
+                    req.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
+                    req.insert("Sec-WebSocket-Version", "13");
                     stream<test::fail_stream<
                         test::string_iostream>> ws{fc, ios_,
                         "\x88\x82\xff\xff\xff\xff\xfc\x17"};
@@ -825,11 +825,11 @@ public:
                     req.method(http::verb::get);
                     req.target("/");
                     req.version = 11;
-                    req.fields.insert("Host", "localhost");
-                    req.fields.insert("Upgrade", "websocket");
-                    req.fields.insert("Connection", "upgrade");
-                    req.fields.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
-                    req.fields.insert("Sec-WebSocket-Version", "13");
+                    req.insert("Host", "localhost");
+                    req.insert("Upgrade", "websocket");
+                    req.insert("Connection", "upgrade");
+                    req.insert("Sec-WebSocket-Key", "dGhlIHNhbXBsZSBub25jZQ==");
+                    req.insert("Sec-WebSocket-Version", "13");
                     stream<test::fail_stream<
                         test::string_iostream>> ws{fc, ios_,
                         "xff\xff\xfc\x17"};
diff --git a/test/websocket/websocket_async_echo_server.hpp b/test/websocket/websocket_async_echo_server.hpp
index 19a51449..db7d2d49 100644
--- a/test/websocket/websocket_async_echo_server.hpp
+++ b/test/websocket/websocket_async_echo_server.hpp
@@ -263,7 +263,7 @@ private:
             d.ws.async_accept_ex(
                 [](beast::websocket::response_type& res)
                 {
-                    res.fields.insert(
+                    res.insert(
                         "Server", "async_echo_server");
                 },
                 std::move(*this));
diff --git a/test/websocket/websocket_sync_echo_server.hpp b/test/websocket/websocket_sync_echo_server.hpp
index 4350cb00..ad683dea 100644
--- a/test/websocket/websocket_sync_echo_server.hpp
+++ b/test/websocket/websocket_sync_echo_server.hpp
@@ -293,7 +293,7 @@ private:
         ws.accept_ex(
             [](beast::websocket::response_type& res)
             {
-                res.fields.insert(
+                res.insert(
                     "Server", "sync_echo_server");
             },
             ec);