diff --git a/CHANGELOG.md b/CHANGELOG.md
index e88dcd86..32d5bfa8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,16 @@
+Version 116:
+
+API Changes:
+
+* message::body is a member function
+
+Actions Required:
+
+* Call member function message::body instead of accessing
+  the data member at call sites.
+
+--------------------------------------------------------------------------------
+
 Version 115:
 
 * Update README.md master doc link
diff --git a/example/advanced/server-flex/advanced_server_flex.cpp b/example/advanced/server-flex/advanced_server_flex.cpp
index 698ce54a..86b4e0d6 100644
--- a/example/advanced/server-flex/advanced_server_flex.cpp
+++ b/example/advanced/server-flex/advanced_server_flex.cpp
@@ -124,7 +124,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -137,7 +137,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -150,7 +150,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/advanced/server/advanced_server.cpp b/example/advanced/server/advanced_server.cpp
index fb1926a4..186d1de2 100644
--- a/example/advanced/server/advanced_server.cpp
+++ b/example/advanced/server/advanced_server.cpp
@@ -118,7 +118,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -131,7 +131,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -144,7 +144,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/doc/http_examples.hpp b/example/doc/http_examples.hpp
index 00f838f6..3c33f373 100644
--- a/example/doc/http_examples.hpp
+++ b/example/doc/http_examples.hpp
@@ -210,8 +210,8 @@ send_cgi_response(
     // that it might be coming later. Otherwise the
     // serializer::is_done would return true right after
     // sending the header.
-    res.body.data = nullptr;
-    res.body.more = true;
+    res.body().data = nullptr;
+    res.body().more = true;
 
     // Create the serializer.
     response_serializer<buffer_body, fields> sr{res};
@@ -235,10 +235,10 @@ send_cgi_response(
             ec = {};
 
             // `nullptr` indicates there is no buffer
-            res.body.data = nullptr;
+            res.body().data = nullptr;
 
             // `false` means no more data is coming
-            res.body.more = false;
+            res.body().more = false;
         }
         else
         {
@@ -248,9 +248,9 @@ send_cgi_response(
             // Point to our buffer with the bytes that
             // we received, and indicate that there may
             // be some more data coming
-            res.body.data = buffer;
-            res.body.size = bytes_transferred;
-            res.body.more = true;
+            res.body().data = buffer;
+            res.body().size = bytes_transferred;
+            res.body().more = true;
         }
             
         // Write everything in the body buffer
@@ -328,7 +328,7 @@ void do_server_head(
             // We deliver the same payload for GET requests
             // regardless of the target. A real server might
             // deliver a file based on the target.
-            res.body = payload;
+            res.body() = payload;
         }
         break;
     }
@@ -339,7 +339,7 @@ void do_server_head(
         // we do not recognize the request method.
         res.result(status::bad_request);
         res.set(field::content_type, "text/plain");
-        res.body = "Invalid request-method '" + req.method_string().to_string() + "'";
+        res.body() = "Invalid request-method '" + req.method_string().to_string() + "'";
         res.prepare_payload();
         break;
     }
@@ -520,8 +520,8 @@ relay(
         if(! p.is_done())
         {
             // Set up the body for writing into our small buffer
-            p.get().body.data = buf;
-            p.get().body.size = sizeof(buf);
+            p.get().body().data = buf;
+            p.get().body().size = sizeof(buf);
 
             // Read as much as we can
             read(input, buffer, p, ec);
@@ -534,14 +534,14 @@ relay(
 
             // Set up the body for reading.
             // This is how much was parsed:
-            p.get().body.size = sizeof(buf) - p.get().body.size;
-            p.get().body.data = buf;
-            p.get().body.more = ! p.is_done();
+            p.get().body().size = sizeof(buf) - p.get().body().size;
+            p.get().body().data = buf;
+            p.get().body().more = ! p.is_done();
         }
         else
         {
-            p.get().body.data = nullptr;
-            p.get().body.size = 0;
+            p.get().body().data = nullptr;
+            p.get().body().size = 0;
         }
 
         // Write everything in the buffer (which might be empty)
@@ -1095,14 +1095,14 @@ read_and_print_body(
     while(! p.is_done())
     {
         char buf[512];
-        p.get().body.data = buf;
-        p.get().body.size = sizeof(buf);
+        p.get().body().data = buf;
+        p.get().body().size = sizeof(buf);
         read(stream, buffer, p, ec);
         if(ec == error::need_buffer)
             ec.assign(0, ec.category());
         if(ec)
             return;
-        os.write(buf, sizeof(buf) - p.get().body.size);
+        os.write(buf, sizeof(buf) - p.get().body().size);
     }
 }
 
diff --git a/example/http/server/async-ssl/http_server_async_ssl.cpp b/example/http/server/async-ssl/http_server_async_ssl.cpp
index 4dff6ed4..d0c4168d 100644
--- a/example/http/server/async-ssl/http_server_async_ssl.cpp
+++ b/example/http/server/async-ssl/http_server_async_ssl.cpp
@@ -119,7 +119,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -132,7 +132,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -145,7 +145,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/async/http_server_async.cpp b/example/http/server/async/http_server_async.cpp
index 5c3f96e6..297be65a 100644
--- a/example/http/server/async/http_server_async.cpp
+++ b/example/http/server/async/http_server_async.cpp
@@ -115,7 +115,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -128,7 +128,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -141,7 +141,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/coro-ssl/http_server_coro_ssl.cpp b/example/http/server/coro-ssl/http_server_coro_ssl.cpp
index 592a1fde..df7ab677 100644
--- a/example/http/server/coro-ssl/http_server_coro_ssl.cpp
+++ b/example/http/server/coro-ssl/http_server_coro_ssl.cpp
@@ -118,7 +118,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -131,7 +131,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -144,7 +144,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/coro/http_server_coro.cpp b/example/http/server/coro/http_server_coro.cpp
index 2a9e63ed..2e42cf86 100644
--- a/example/http/server/coro/http_server_coro.cpp
+++ b/example/http/server/coro/http_server_coro.cpp
@@ -114,7 +114,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -127,7 +127,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -140,7 +140,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/fast/http_server_fast.cpp b/example/http/server/fast/http_server_fast.cpp
index e470c508..06be184d 100644
--- a/example/http/server/fast/http_server_fast.cpp
+++ b/example/http/server/fast/http_server_fast.cpp
@@ -212,7 +212,7 @@ private:
         string_response_->set(http::field::server, "Beast");
         string_response_->set(http::field::connection, "close");
         string_response_->set(http::field::content_type, "text/plain");
-        string_response_->body = error;
+        string_response_->body() = error;
         string_response_->prepare_payload();
 
         string_serializer_.emplace(*string_response_);
@@ -268,7 +268,7 @@ private:
         file_response_->set(http::field::server, "Beast");
         file_response_->set(http::field::connection, "close");
         file_response_->set(http::field::content_type, mime_type(target.to_string()));
-        file_response_->body = std::move(file);
+        file_response_->body() = std::move(file);
         file_response_->prepare_payload();
 
         file_serializer_.emplace(*file_response_);
diff --git a/example/http/server/flex/http_server_flex.cpp b/example/http/server/flex/http_server_flex.cpp
index 85749ad5..2bb538de 100644
--- a/example/http/server/flex/http_server_flex.cpp
+++ b/example/http/server/flex/http_server_flex.cpp
@@ -119,7 +119,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -132,7 +132,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -145,7 +145,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/small/http_server_small.cpp b/example/http/server/small/http_server_small.cpp
index 8ed8d422..1f26484e 100644
--- a/example/http/server/small/http_server_small.cpp
+++ b/example/http/server/small/http_server_small.cpp
@@ -116,7 +116,7 @@ private:
             // we do not recognize the request method.
             response_.result(http::status::bad_request);
             response_.set(http::field::content_type, "text/plain");
-            boost::beast::ostream(response_.body)
+            boost::beast::ostream(response_.body())
                 << "Invalid request-method '"
                 << request_.method_string().to_string()
                 << "'";
@@ -133,7 +133,7 @@ private:
         if(request_.target() == "/count")
         {
             response_.set(http::field::content_type, "text/html");
-            boost::beast::ostream(response_.body)
+            boost::beast::ostream(response_.body())
                 << "<html>\n"
                 <<  "<head><title>Request count</title></head>\n"
                 <<  "<body>\n"
@@ -147,7 +147,7 @@ private:
         else if(request_.target() == "/time")
         {
             response_.set(http::field::content_type, "text/html");
-            boost::beast::ostream(response_.body)
+            boost::beast::ostream(response_.body())
                 <<  "<html>\n"
                 <<  "<head><title>Current time</title></head>\n"
                 <<  "<body>\n"
@@ -162,7 +162,7 @@ private:
         {
             response_.result(http::status::not_found);
             response_.set(http::field::content_type, "text/plain");
-            boost::beast::ostream(response_.body) << "File not found\r\n";
+            boost::beast::ostream(response_.body()) << "File not found\r\n";
         }
     }
 
@@ -172,7 +172,7 @@ private:
     {
         auto self = shared_from_this();
 
-        response_.set(http::field::content_length, response_.body.size());
+        response_.set(http::field::content_length, response_.body().size());
 
         http::async_write(
             socket_,
diff --git a/example/http/server/stackless-ssl/http_server_stackless_ssl.cpp b/example/http/server/stackless-ssl/http_server_stackless_ssl.cpp
index c7386e4b..9d0352af 100644
--- a/example/http/server/stackless-ssl/http_server_stackless_ssl.cpp
+++ b/example/http/server/stackless-ssl/http_server_stackless_ssl.cpp
@@ -120,7 +120,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -133,7 +133,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -146,7 +146,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/stackless/http_server_stackless.cpp b/example/http/server/stackless/http_server_stackless.cpp
index 4db45ab2..50af6c35 100644
--- a/example/http/server/stackless/http_server_stackless.cpp
+++ b/example/http/server/stackless/http_server_stackless.cpp
@@ -116,7 +116,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -129,7 +129,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -142,7 +142,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/sync-ssl/http_server_sync_ssl.cpp b/example/http/server/sync-ssl/http_server_sync_ssl.cpp
index d6c7c34e..87901c92 100644
--- a/example/http/server/sync-ssl/http_server_sync_ssl.cpp
+++ b/example/http/server/sync-ssl/http_server_sync_ssl.cpp
@@ -115,7 +115,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -128,7 +128,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -141,7 +141,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/example/http/server/sync/http_server_sync.cpp b/example/http/server/sync/http_server_sync.cpp
index 0a813448..1aaf3162 100644
--- a/example/http/server/sync/http_server_sync.cpp
+++ b/example/http/server/sync/http_server_sync.cpp
@@ -113,7 +113,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = why.to_string();
+        res.body() = why.to_string();
         res.prepare_payload();
         return res;
     };
@@ -126,7 +126,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "The resource '" + target.to_string() + "' was not found.";
+        res.body() = "The resource '" + target.to_string() + "' was not found.";
         res.prepare_payload();
         return res;
     };
@@ -139,7 +139,7 @@ handle_request(
         res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
         res.set(http::field::content_type, "text/html");
         res.keep_alive(req.keep_alive());
-        res.body = "An error occurred: '" + what.to_string() + "'";
+        res.body() = "An error occurred: '" + what.to_string() + "'";
         res.prepare_payload();
         return res;
     };
diff --git a/include/boost/beast/core/detail/empty_base_optimization.hpp b/include/boost/beast/core/detail/empty_base_optimization.hpp
index f2e6dace..b1e728b6 100644
--- a/include/boost/beast/core/detail/empty_base_optimization.hpp
+++ b/include/boost/beast/core/detail/empty_base_optimization.hpp
@@ -19,31 +19,32 @@ namespace beast {
 namespace detail {
 
 template<class T>
-struct empty_base_optimization_decide
+struct is_empty_base_optimization_derived
     : std::integral_constant<bool,
         std::is_empty<T>::value &&
         ! boost::is_final<T>::value>
 {
 };
 
-template<
-    class T,
-    int UniqueID = 0,
-    bool ShouldDeriveFrom =
-        empty_base_optimization_decide<T>::value
->
+template<class T, int UniqueID = 0,
+    bool isDerived =
+        is_empty_base_optimization_derived<T>::value>
 class empty_base_optimization : private T
 {
 public:
     empty_base_optimization() = default;
+    empty_base_optimization(empty_base_optimization&&) = default;
+    empty_base_optimization(empty_base_optimization const&) = default;
+    empty_base_optimization& operator=(empty_base_optimization&&) = default;
+    empty_base_optimization& operator=(empty_base_optimization const&) = default;
 
-    empty_base_optimization(T const& t)
-        : T (t)
-    {}
-
-    empty_base_optimization(T&& t)
-        : T (std::move (t))
-    {}
+    template<class Arg1, class... ArgN>
+    explicit
+    empty_base_optimization(Arg1&& arg1, ArgN&&... argn)
+        : T(std::forward<Arg1>(arg1),
+            std::forward<ArgN>(argn)...)
+    {
+    }
 
     T& member() noexcept
     {
@@ -64,29 +65,32 @@ template<
 >
 class empty_base_optimization <T, UniqueID, false>
 {
+    T t_;
+
 public:
     empty_base_optimization() = default;
+    empty_base_optimization(empty_base_optimization&&) = default;
+    empty_base_optimization(empty_base_optimization const&) = default;
+    empty_base_optimization& operator=(empty_base_optimization&&) = default;
+    empty_base_optimization& operator=(empty_base_optimization const&) = default;
 
-    empty_base_optimization(T const& t)
-        : m_t (t)
-    {}
-
-    empty_base_optimization(T&& t)
-        : m_t (std::move (t))
-    {}
+    template<class Arg1, class... ArgN>
+    explicit
+    empty_base_optimization(Arg1&& arg1, ArgN&&... argn)
+        : t_(std::forward<Arg1>(arg1),
+            std::forward<ArgN>(argn)...)
+    {
+    }
 
     T& member() noexcept
     {
-        return m_t;
+        return t_;
     }
 
     T const& member() const noexcept
     {
-        return m_t;
+        return t_;
     }
-
-private:
-    T m_t;
 };
 
 } // detail
diff --git a/include/boost/beast/http/basic_dynamic_body.hpp b/include/boost/beast/http/basic_dynamic_body.hpp
index f6fde1c0..416f4239 100644
--- a/include/boost/beast/http/basic_dynamic_body.hpp
+++ b/include/boost/beast/http/basic_dynamic_body.hpp
@@ -74,7 +74,7 @@ struct basic_dynamic_body
         explicit
         reader(message<isRequest,
                 basic_dynamic_body, Fields> const& m)
-            : body_(m.body)
+            : body_(m.body())
         {
         }
 
@@ -109,7 +109,7 @@ struct basic_dynamic_body
         explicit
         writer(message<isRequest,
                 basic_dynamic_body, Fields>& msg)
-            : body_(msg.body)
+            : body_(msg.body())
         {
         }
 
diff --git a/include/boost/beast/http/basic_file_body.hpp b/include/boost/beast/http/basic_file_body.hpp
index c76546fa..c6b25044 100644
--- a/include/boost/beast/http/basic_file_body.hpp
+++ b/include/boost/beast/http/basic_file_body.hpp
@@ -291,7 +291,7 @@ template<bool isRequest, class Fields>
 basic_file_body<File>::
 reader::
 reader(message<isRequest, basic_file_body, Fields>& m)
-    : body_(m.body)
+    : body_(m.body())
 {
     // The file must already be open
     BOOST_ASSERT(body_.file_.is_open());
@@ -442,7 +442,7 @@ template<bool isRequest, class Fields>
 basic_file_body<File>::
 writer::
 writer(message<isRequest, basic_file_body, Fields>& m)
-    : body_(m.body)
+    : body_(m.body())
 {
 }
 
diff --git a/include/boost/beast/http/buffer_body.hpp b/include/boost/beast/http/buffer_body.hpp
index 9473d84a..780e63ee 100644
--- a/include/boost/beast/http/buffer_body.hpp
+++ b/include/boost/beast/http/buffer_body.hpp
@@ -111,7 +111,7 @@ struct buffer_body
         explicit
         reader(message<isRequest,
                 buffer_body, Fields> const& msg)
-            : body_(msg.body)
+            : body_(msg.body())
         {
         }
 
@@ -169,7 +169,7 @@ struct buffer_body
         template<bool isRequest, class Fields>
         explicit
         writer(message<isRequest, buffer_body, Fields>& m)
-            : body_(m.body)
+            : body_(m.body())
         {
         }
 
diff --git a/include/boost/beast/http/impl/file_body_win32.ipp b/include/boost/beast/http/impl/file_body_win32.ipp
index c1191538..1ef2472e 100644
--- a/include/boost/beast/http/impl/file_body_win32.ipp
+++ b/include/boost/beast/http/impl/file_body_win32.ipp
@@ -125,7 +125,7 @@ struct basic_file_body<file_win32>
         template<bool isRequest, class Fields>
         reader(message<isRequest,
                 basic_file_body<file_win32>, Fields>& m)
-            : body_(m.body)
+            : body_(m.body())
         {
         }
 
@@ -168,7 +168,7 @@ struct basic_file_body<file_win32>
         template<bool isRequest, class Fields>
         explicit
         writer(message<isRequest, basic_file_body, Fields>& m)
-            : body_(m.body)
+            : body_(m.body())
         {
         }
 
@@ -437,7 +437,7 @@ operator()()
     ov.OffsetHigh = highPart(r.pos_);
     auto const bSuccess = ::TransmitFile(
         sock_.native_handle(),
-        sr_.get().body.file_.native_handle(),
+        sr_.get().body().file_.native_handle(),
         nNumberOfBytesToWrite,
         0,
         overlapped.get(),
diff --git a/include/boost/beast/http/impl/message.ipp b/include/boost/beast/http/impl/message.ipp
index 93abbafb..fc19ec27 100644
--- a/include/boost/beast/http/impl/message.ipp
+++ b/include/boost/beast/http/impl/message.ipp
@@ -209,7 +209,9 @@ template<class... BodyArgs>
 message<isRequest, Body, Fields>::
 message(header_type&& h, BodyArgs&&... body_args)
     : header_type(std::move(h))
-    , body(std::forward<BodyArgs>(body_args)...)
+    , beast::detail::empty_base_optimization<
+        typename Body::value_type>(
+            std::forward<BodyArgs>(body_args)...)
 {
 }
 
@@ -218,7 +220,9 @@ template<class... BodyArgs>
 message<isRequest, Body, Fields>::
 message(header_type const& h, BodyArgs&&... body_args)
     : header_type(h)
-    , body(std::forward<BodyArgs>(body_args)...)
+    , beast::detail::empty_base_optimization<
+        typename Body::value_type>(
+            std::forward<BodyArgs>(body_args)...)
 {
 }
 
@@ -236,7 +240,9 @@ message<isRequest, Body, Fields>::
 message(verb method, string_view target,
         Version version, BodyArg&& body_arg)
     : header_type(method, target, version)
-    , body(std::forward<BodyArg>(body_arg))
+    , beast::detail::empty_base_optimization<
+        typename Body::value_type>(
+            std::forward<BodyArg>(body_arg))
 {
 }
 
@@ -249,7 +255,9 @@ message(
     FieldsArg&& fields_arg)
     : header_type(method, target, version,
         std::forward<FieldsArg>(fields_arg))
-    , body(std::forward<BodyArg>(body_arg))
+    , beast::detail::empty_base_optimization<
+        typename Body::value_type>(
+            std::forward<BodyArg>(body_arg))
 {
 }
 
@@ -267,7 +275,9 @@ message<isRequest, Body, Fields>::
 message(status result, Version version,
     BodyArg&& body_arg)
     : header_type(result, version)
-    , body(std::forward<BodyArg>(body_arg))
+    , beast::detail::empty_base_optimization<
+        typename Body::value_type>(
+            std::forward<BodyArg>(body_arg))
 {
 }
 
@@ -278,7 +288,9 @@ message(status result, Version version,
     BodyArg&& body_arg, FieldsArg&& fields_arg)
     : header_type(result, version,
         std::forward<FieldsArg>(fields_arg))
-    , body(std::forward<BodyArg>(body_arg))
+    , beast::detail::empty_base_optimization<
+        typename Body::value_type>(
+            std::forward<BodyArg>(body_arg))
 {
 }
 
@@ -409,7 +421,7 @@ swap(
     swap(
         static_cast<header<isRequest, Fields>&>(m1),
         static_cast<header<isRequest, Fields>&>(m2));
-    swap(m1.body, m2.body);
+    swap(m1.body(), m2.body());
 }
 
 } // http
diff --git a/include/boost/beast/http/message.hpp b/include/boost/beast/http/message.hpp
index adf1fbe9..a2868318 100644
--- a/include/boost/beast/http/message.hpp
+++ b/include/boost/beast/http/message.hpp
@@ -16,6 +16,7 @@
 #include <boost/beast/http/status.hpp>
 #include <boost/beast/http/type_traits.hpp>
 #include <boost/beast/core/string.hpp>
+#include <boost/beast/core/detail/empty_base_optimization.hpp>
 #include <boost/beast/core/detail/integer_sequence.hpp>
 #include <boost/optional.hpp>
 #include <boost/throw_exception.hpp>
@@ -391,6 +392,14 @@ using request_header = header<true, Fields>;
 template<class Fields = fields>
 using response_header = header<false, Fields>;
 
+#if defined(BOOST_MSVC)
+// Workaround for MSVC bug with private base classes
+namespace detail {
+template<class T>
+using value_type_t = typename T::value_type;
+} // detail
+#endif
+
 /** A container for a complete HTTP message.
 
     This container is derived from the `Fields` template type.
@@ -421,7 +430,12 @@ using response_header = header<false, Fields>;
     field value pairs.
 */
 template<bool isRequest, class Body, class Fields = fields>
-struct message : header<isRequest, Fields>
+struct message
+    : header<isRequest, Fields>
+#if ! BOOST_BEAST_DOXYGEN
+    , beast::detail::empty_base_optimization<
+        typename Body::value_type>
+#endif
 {
     /// The base class used to hold the header portion of the message.
     using header_type = header<isRequest, Fields>;
@@ -432,9 +446,6 @@ struct message : header<isRequest, Fields>
     */
     using body_type = Body;
 
-    /// A value representing the body.
-    typename Body::value_type body;
-
     /// Constructor
     message() = default;
 
@@ -736,7 +747,7 @@ struct message : header<isRequest, Fields>
         @code
         request<string_body> req{verb::post, "/"};
         req.set(field::user_agent, "Beast");
-        req.body = "Hello, world!";
+        req.body() = "Hello, world!";
         req.prepare_payload();
         @endcode
     */
@@ -746,6 +757,28 @@ struct message : header<isRequest, Fields>
         prepare_payload(typename header_type::is_request{});
     }
 
+    /// Returns the body
+#if BOOST_BEAST_DOXYGEN || ! defined(BOOST_MSVC)
+    typename body_type::value_type&
+#else
+    detail::value_type_t<Body>&
+#endif
+    body() noexcept
+    {
+        return this->member();
+    }
+
+    /// Returns the body
+#if BOOST_BEAST_DOXYGEN || ! defined(BOOST_MSVC)
+    typename body_type::value_type const&
+#else
+    detail::value_type_t<Body> const&
+#endif
+    body() const noexcept
+    {
+        return this->member();
+    }
+
 private:
     static_assert(is_body<Body>::value,
         "Body requirements not met");
@@ -757,8 +790,10 @@ private:
         std::piecewise_construct_t,
         std::tuple<BodyArgs...>& body_args,
         beast::detail::index_sequence<IBodyArgs...>)
-        : body(std::forward<BodyArgs>(
-            std::get<IBodyArgs>(body_args))...)
+        : beast::detail::empty_base_optimization<
+            typename Body::value_type>(
+                std::forward<BodyArgs>(
+                std::get<IBodyArgs>(body_args))...)
     {
         boost::ignore_unused(body_args);
     }
@@ -776,8 +811,10 @@ private:
         beast::detail::index_sequence<IFieldsArgs...>)
         : header_type(std::forward<FieldsArgs>(
             std::get<IFieldsArgs>(fields_args))...)
-        , body(std::forward<BodyArgs>(
-            std::get<IBodyArgs>(body_args))...)
+        , beast::detail::empty_base_optimization<
+            typename Body::value_type>(
+                std::forward<BodyArgs>(
+                std::get<IBodyArgs>(body_args))...)
     {
         boost::ignore_unused(body_args);
         boost::ignore_unused(fields_args);
@@ -786,7 +823,7 @@ private:
     boost::optional<std::uint64_t>
     payload_size(std::true_type) const
     {
-        return Body::size(body);
+        return Body::size(this->body());
     }
 
     boost::optional<std::uint64_t>
diff --git a/include/boost/beast/http/span_body.hpp b/include/boost/beast/http/span_body.hpp
index 9c6f561f..3530179b 100644
--- a/include/boost/beast/http/span_body.hpp
+++ b/include/boost/beast/http/span_body.hpp
@@ -78,7 +78,7 @@ public:
         explicit
         reader(message<isRequest,
                 span_body, Fields> const& msg)
-            : body_(msg.body)
+            : body_(msg.body())
         {
         }
 
@@ -117,7 +117,7 @@ public:
         explicit
         writer(message<isRequest,
                 span_body, Fields>& m)
-            : body_(m.body)
+            : body_(m.body())
         {
         }
 
diff --git a/include/boost/beast/http/string_body.hpp b/include/boost/beast/http/string_body.hpp
index cd94243d..25523c9a 100644
--- a/include/boost/beast/http/string_body.hpp
+++ b/include/boost/beast/http/string_body.hpp
@@ -86,7 +86,7 @@ public:
         explicit
         reader(message<isRequest,
                 basic_string_body, Fields> const& msg)
-            : body_(msg.body)
+            : body_(msg.body())
         {
         }
 
@@ -122,7 +122,7 @@ public:
         explicit
         writer(message<isRequest,
                 basic_string_body, Fields>& m)
-            : body_(m.body)
+            : body_(m.body())
         {
         }
 
diff --git a/include/boost/beast/http/vector_body.hpp b/include/boost/beast/http/vector_body.hpp
index d9d00b60..e4ab3ea1 100644
--- a/include/boost/beast/http/vector_body.hpp
+++ b/include/boost/beast/http/vector_body.hpp
@@ -81,7 +81,7 @@ public:
         explicit
         reader(message<isRequest,
                 vector_body, Fields> const& msg)
-            : body_(msg.body)
+            : body_(msg.body())
         {
         }
 
@@ -117,7 +117,7 @@ public:
         explicit
         writer(message<isRequest,
                 vector_body, Fields>& m)
-            : body_(m.body)
+            : body_(m.body())
         {
         }
 
diff --git a/include/boost/beast/websocket/impl/stream.ipp b/include/boost/beast/websocket/impl/stream.ipp
index b783a9a5..d02d7710 100644
--- a/include/boost/beast/websocket/impl/stream.ipp
+++ b/include/boost/beast/websocket/impl/stream.ipp
@@ -577,7 +577,7 @@ build_response(http::request<Body,
             response_type res;
             res.version = req.version;
             res.result(http::status::bad_request);
-            res.body = text;
+            res.body() = text;
             res.prepare_payload();
             decorate(res);
             return res;
diff --git a/test/beast/http/dynamic_body.cpp b/test/beast/http/dynamic_body.cpp
index 80bcd044..a81f88b0 100644
--- a/test/beast/http/dynamic_body.cpp
+++ b/test/beast/http/dynamic_body.cpp
@@ -66,7 +66,7 @@ public:
         multi_buffer b;
         read(ts, b, p);
         auto const& m = p.get();
-        BEAST_EXPECT(to_string(m.body.data()) == "xyz");
+        BEAST_EXPECT(to_string(m.body().data()) == "xyz");
         BEAST_EXPECT(to_string(m) == s);
     }
 };
diff --git a/test/beast/http/fields.cpp b/test/beast/http/fields.cpp
index 5ed766a6..c54871c2 100644
--- a/test/beast/http/fields.cpp
+++ b/test/beast/http/fields.cpp
@@ -475,7 +475,7 @@ public:
             request<sized_body> req;
             req.version = 11;
             req.method(verb::get);
-            req.body = 50;
+            req.body() = 50;
 
             req.prepare_payload();
             BEAST_EXPECT(req[field::content_length] == "50");
@@ -515,7 +515,7 @@ public:
             request<sized_body> req;
             req.version = 11;
             req.method(verb::put);
-            req.body = 50;
+            req.body() = 50;
 
             req.prepare_payload();
             BEAST_EXPECT(req[field::content_length] == "50");
@@ -580,7 +580,7 @@ public:
         {
             response<sized_body> res;
             res.version = 11;
-            res.body = 50;
+            res.body() = 50;
 
             res.prepare_payload();
             BEAST_EXPECT(res[field::content_length] == "50");
diff --git a/test/beast/http/file_body.cpp b/test/beast/http/file_body.cpp
index 838d38e9..b63a5ce7 100644
--- a/test/beast/http/file_body.cpp
+++ b/test/beast/http/file_body.cpp
@@ -54,7 +54,7 @@ public:
             response_parser<basic_file_body<File>> p;
             p.eager(true);
 
-            p.get().body.open(
+            p.get().body().open(
                 temp.string<std::string>().c_str(), file_mode::write, ec);
             BEAST_EXPECTS(! ec, ec.message());
 
@@ -78,7 +78,7 @@ public:
             {
                 response<basic_file_body<File>> res{status::ok, 11};
                 res.set(field::server, "test");
-                res.body.open(temp.string<std::string>().c_str(),
+                res.body().open(temp.string<std::string>().c_str(),
                     file_mode::scan, ec);
                 BEAST_EXPECTS(! ec, ec.message());
                 res.prepare_payload();
diff --git a/test/beast/http/message.cpp b/test/beast/http/message.cpp
index 61079c9f..b229552e 100644
--- a/test/beast/http/message.cpp
+++ b/test/beast/http/message.cpp
@@ -156,17 +156,17 @@ public:
         request<string_body> m1;
         request<string_body> m2;
         m1.target("u");
-        m1.body = "1";
+        m1.body() = "1";
         m1.insert("h", "v");
         m2.method_string("G");
-        m2.body = "2";
+        m2.body() = "2";
         swap(m1, m2);
         BEAST_EXPECT(m1.method_string() == "G");
         BEAST_EXPECT(m2.method_string().empty());
         BEAST_EXPECT(m1.target().empty());
         BEAST_EXPECT(m2.target() == "u");
-        BEAST_EXPECT(m1.body == "2");
-        BEAST_EXPECT(m2.body == "1");
+        BEAST_EXPECT(m1.body() == "2");
+        BEAST_EXPECT(m2.body() == "1");
         BEAST_EXPECT(! m1.count("h"));
         BEAST_EXPECT(m2.count("h"));
     }
@@ -231,7 +231,7 @@ public:
             BEAST_EXPECT(req.version == 11);
             BEAST_EXPECT(req.method() == verb::get);
             BEAST_EXPECT(req.target() == "/");
-            BEAST_EXPECT(req.body == "Hello");
+            BEAST_EXPECT(req.body() == "Hello");
         }
         {
             request<string_body, test_fields> req{
@@ -239,7 +239,7 @@ public:
             BEAST_EXPECT(req.version == 11);
             BEAST_EXPECT(req.method() == verb::get);
             BEAST_EXPECT(req.target() == "/");
-            BEAST_EXPECT(req.body == "Hello");
+            BEAST_EXPECT(req.body() == "Hello");
         }
         {
             response<string_body> res;
@@ -258,7 +258,7 @@ public:
             BEAST_EXPECT(res.version == 10);
             BEAST_EXPECT(res.result() == status::bad_request);
             BEAST_EXPECT(res.reason() == "Bad Request");
-            BEAST_EXPECT(res.body == "Hello");
+            BEAST_EXPECT(res.body() == "Hello");
         }
         {
             response<string_body, test_fields> res{
@@ -266,7 +266,7 @@ public:
             BEAST_EXPECT(res.version == 10);
             BEAST_EXPECT(res.result() == status::bad_request);
             BEAST_EXPECT(res.reason() == "Bad Request");
-            BEAST_EXPECT(res.body == "Hello");
+            BEAST_EXPECT(res.body() == "Hello");
         }
     }
 
@@ -277,10 +277,10 @@ public:
         response<string_body> m2;
         m1.result(status::ok);
         m1.version = 10;
-        m1.body = "1";
+        m1.body() = "1";
         m1.insert("h", "v");
         m2.result(status::not_found);
-        m2.body = "2";
+        m2.body() = "2";
         m2.version = 11;
         swap(m1, m2);
         BEAST_EXPECT(m1.result() == status::not_found);
@@ -291,8 +291,8 @@ public:
         BEAST_EXPECT(m2.reason() == "OK");
         BEAST_EXPECT(m1.version == 11);
         BEAST_EXPECT(m2.version == 10);
-        BEAST_EXPECT(m1.body == "2");
-        BEAST_EXPECT(m2.body == "1");
+        BEAST_EXPECT(m1.body() == "2");
+        BEAST_EXPECT(m2.body() == "1");
         BEAST_EXPECT(! m1.count("h"));
         BEAST_EXPECT(m2.count("h"));
     }
diff --git a/test/beast/http/parser.cpp b/test/beast/http/parser.cpp
index ebc5558a..f618bcc1 100644
--- a/test/beast/http/parser.cpp
+++ b/test/beast/http/parser.cpp
@@ -135,7 +135,7 @@ public:
                 BEAST_EXPECT(m.result() == status::ok);
                 BEAST_EXPECT(m.reason() == "OK");
                 BEAST_EXPECT(m["Server"] == "test");
-                BEAST_EXPECT(m.body == "Hello, world!");
+                BEAST_EXPECT(m.body() == "Hello, world!");
             }
         );
         doMatrix<false>(
@@ -165,7 +165,7 @@ public:
                 BEAST_EXPECT(m["Transfer-Encoding"] == "chunked");
                 BEAST_EXPECT(m["Expires"] == "never");
                 BEAST_EXPECT(m["MD5-Fingerprint"] == "-");
-                BEAST_EXPECT(m.body == "*****--");
+                BEAST_EXPECT(m.body() == "*****--");
             }
         );
         doMatrix<false>(
@@ -177,7 +177,7 @@ public:
             [&](parser_type<false> const& p)
             {
                 auto const& m = p.get();
-                BEAST_EXPECT(m.body == "*****");
+                BEAST_EXPECT(m.body() == "*****");
             }
         );
         doMatrix<true>(
@@ -228,7 +228,7 @@ public:
             BEAST_EXPECT(m.target() == "/");
             BEAST_EXPECT(m.version == 11);
             BEAST_EXPECT(m["User-Agent"] == "test");
-            BEAST_EXPECT(m.body == "*");
+            BEAST_EXPECT(m.body() == "*");
         }
         {
             // test partial parsing of final chunk
@@ -247,7 +247,7 @@ public:
             b.consume(used);
             BEAST_EXPECT(! ec);
             BEAST_EXPECT(! p.is_done());
-            BEAST_EXPECT(p.get().body == "*");
+            BEAST_EXPECT(p.get().body() == "*");
             ostream(b) <<
                 "\r\n"
                 "0;d;e=3;f=\"4\"\r\n"
diff --git a/test/beast/http/serializer.cpp b/test/beast/http/serializer.cpp
index 171333d4..3d364730 100644
--- a/test/beast/http/serializer.cpp
+++ b/test/beast/http/serializer.cpp
@@ -102,7 +102,7 @@ public:
         lambda visit;
         error_code ec;
         response<string_body> res;
-        res.body.append(1000, '*');
+        res.body().append(1000, '*');
         serializer<false, string_body> sr{res};
         sr.limit(limit);
         for(;;)
diff --git a/test/beast/http/span_body.cpp b/test/beast/http/span_body.cpp
index e6e9aa13..2dbf2c0f 100644
--- a/test/beast/http/span_body.cpp
+++ b/test/beast/http/span_body.cpp
@@ -27,12 +27,12 @@ struct span_body_test
             using B = span_body<char const>;
             request<B> req;
 
-            BEAST_EXPECT(req.body.size() == 0);
-            BEAST_EXPECT(B::size(req.body) == 0);
+            BEAST_EXPECT(req.body().size() == 0);
+            BEAST_EXPECT(B::size(req.body()) == 0);
 
-            req.body = B::value_type("xyz", 3);
-            BEAST_EXPECT(req.body.size() == 3);
-            BEAST_EXPECT(B::size(req.body) == 3);
+            req.body() = B::value_type("xyz", 3);
+            BEAST_EXPECT(req.body().size() == 3);
+            BEAST_EXPECT(B::size(req.body()) == 3);
 
             B::reader r{req};
             error_code ec;
@@ -49,7 +49,7 @@ struct span_body_test
             char buf[5];
             using B = span_body<char>;
             request<B> req;
-            req.body = span<char>{buf, sizeof(buf)};
+            req.body() = span<char>{buf, sizeof(buf)};
             B::writer w{req};
             error_code ec;
             w.init(boost::none, ec);
diff --git a/test/beast/http/write.cpp b/test/beast/http/write.cpp
index 7d4ccfdc..d4a8fbeb 100644
--- a/test/beast/http/write.cpp
+++ b/test/beast/http/write.cpp
@@ -50,7 +50,7 @@ public:
             explicit
             reader(message<isRequest,
                     unsized_body, Allocator> const& msg)
-                : body_(msg.body)
+                : body_(msg.body())
             {
             }
 
@@ -95,7 +95,7 @@ public:
             explicit
             reader(message<isRequest,
                     test_body, Fields> const& msg)
-                : body_(msg.body)
+                : body_(msg.body())
             {
             }
 
@@ -232,7 +232,7 @@ public:
             explicit
             reader(message<isRequest,
                     fail_body, Allocator> const& msg)
-                : body_(msg.body)
+                : body_(msg.body())
             {
             }
 
@@ -292,7 +292,7 @@ public:
         try
         {
             read(ts, b, m);
-            return m.body == body;
+            return m.body() == body;
         }
         catch(std::exception const& e)
         {
@@ -323,7 +323,7 @@ public:
             m.result(status::ok);
             m.set(field::server, "test");
             m.set(field::content_length, "5");
-            m.body = "*****";
+            m.body() = "*****";
             error_code ec;
             test::stream ts{ios_}, tr{ios_};
             ts.connect(tr);
@@ -342,7 +342,7 @@ public:
             m.result(status::ok);
             m.set(field::server, "test");
             m.set(field::transfer_encoding, "chunked");
-            m.body = "*****";
+            m.body() = "*****";
             error_code ec;
             test::stream ts{ios_}, tr{ios_};
             ts.connect(tr);
@@ -374,7 +374,7 @@ public:
             m.set(field::user_agent, "test");
             m.set(field::connection, "keep-alive");
             m.set(field::content_length, "5");
-            m.body = "*****";
+            m.body() = "*****";
             try
             {
                 write(ts, m);
@@ -403,7 +403,7 @@ public:
             request<fail_body> m{verb::get, "/", 10, fc};
             m.set(field::user_agent, "test");
             m.set(field::transfer_encoding, "chunked");
-            m.body = "*****";
+            m.body() = "*****";
             error_code ec = test::error::fail_error;
             write(ts, m, ec);
             if(ec == error::end_of_stream)
@@ -433,7 +433,7 @@ public:
             request<fail_body> m{verb::get, "/", 10, fc};
             m.set(field::user_agent, "test");
             m.set(field::transfer_encoding, "chunked");
-            m.body = "*****";
+            m.body() = "*****";
             error_code ec = test::error::fail_error;
             async_write(ts, m, do_yield[ec]);
             if(ec == error::end_of_stream)
@@ -464,7 +464,7 @@ public:
             m.set(field::user_agent, "test");
             m.set(field::connection, "keep-alive");
             m.set(field::content_length, "5");
-            m.body = "*****";
+            m.body() = "*****";
             error_code ec = test::error::fail_error;
             write(ts, m, ec);
             if(! ec)
@@ -491,7 +491,7 @@ public:
             m.set(field::user_agent, "test");
             m.set(field::connection, "keep-alive");
             m.set(field::content_length, "5");
-            m.body = "*****";
+            m.body() = "*****";
             error_code ec = test::error::fail_error;
             async_write(ts, m, do_yield[ec]);
             if(! ec)
@@ -520,7 +520,7 @@ public:
             m.target("/");
             m.version = 10;
             m.set(field::user_agent, "test");
-            m.body = "*";
+            m.body() = "*";
             m.prepare_payload();
             BEAST_EXPECT(str(m) ==
                 "GET / HTTP/1.0\r\n"
@@ -537,7 +537,7 @@ public:
             m.target("/");
             m.version = 10;
             m.set(field::user_agent, "test");
-            m.body = "*";
+            m.body() = "*";
             m.prepare_payload();
             test::stream ts{ios_}, tr{ios_};
             ts.connect(tr);
@@ -558,7 +558,7 @@ public:
             m.target("/");
             m.version = 11;
             m.set(field::user_agent, "test");
-            m.body = "*";
+            m.body() = "*";
             m.prepare_payload();
             BEAST_EXPECT(str(m) ==
                 "GET / HTTP/1.1\r\n"
@@ -575,7 +575,7 @@ public:
             m.target("/");
             m.version = 11;
             m.set(field::user_agent, "test");
-            m.body = "*";
+            m.body() = "*";
             m.prepare_payload();
             test::stream ts{ios_}, tr{ios_};
             ts.connect(tr);
@@ -601,7 +601,7 @@ public:
         m.target("/");
         m.version = 11;
         m.set(field::user_agent, "test");
-        m.body = "*";
+        m.body() = "*";
         BEAST_EXPECT(to_string(m) ==
             "GET / HTTP/1.1\r\nUser-Agent: test\r\n\r\n*");
     }
@@ -631,7 +631,7 @@ public:
             m.version = 11;
             m.target("/");
             m.set("Content-Length", 5);
-            m.body = "*****";
+            m.body() = "*****";
             async_write(ts, m, handler{});
             BEAST_EXPECT(handler::count() > 0);
             ios.stop();
@@ -654,7 +654,7 @@ public:
                 m.version = 11;
                 m.target("/");
                 m.set("Content-Length", 5);
-                m.body = "*****";
+                m.body() = "*****";
                 async_write(ts, m, handler{});
                 BEAST_EXPECT(handler::count() > 0);
             }
@@ -716,7 +716,7 @@ public:
         m0.result(status::ok);
         m0.reason("OK");
         m0.set(field::server, "test");
-        m0.body.s = "Hello, world!\n";
+        m0.body().s = "Hello, world!\n";
 
         {
             std::string const result =
@@ -730,7 +730,7 @@ public:
                 do_write(ts, m, ec);
                 BEAST_EXPECT(tr.str() == result);
                 BEAST_EXPECT(equal_body<false>(
-                    tr.str(), m.body.s));
+                    tr.str(), m.body().s));
                 tr.clear();
             }
             {
@@ -739,7 +739,7 @@ public:
                 do_async_write(ts, m, ec, yield);
                 BEAST_EXPECT(tr.str() == result);
                 BEAST_EXPECT(equal_body<false>(
-                    tr.str(), m.body.s));
+                    tr.str(), m.body().s));
                 tr.clear();
             }
             {
@@ -753,7 +753,7 @@ public:
                     if(sr.is_header_done())
                         break;
                 }
-                BEAST_EXPECT(! m.body.read);
+                BEAST_EXPECT(! m.body().read);
                 tr.clear();
             }
             {
@@ -767,7 +767,7 @@ public:
                     if(sr.is_header_done())
                         break;
                 }
-                BEAST_EXPECT(! m.body.read);
+                BEAST_EXPECT(! m.body().read);
                 tr.clear();
             }
         }
@@ -778,7 +778,7 @@ public:
                 error_code ec;
                 do_write(ts, m, ec);
                 BEAST_EXPECT(equal_body<false>(
-                    tr.str(), m.body.s));
+                    tr.str(), m.body().s));
                 tr.clear();
             }
             {
@@ -786,7 +786,7 @@ public:
                 error_code ec;
                 do_async_write(ts, m, ec, yield);
                 BEAST_EXPECT(equal_body<false>(
-                    tr.str(), m.body.s));
+                    tr.str(), m.body().s));
                 tr.clear();
             }
             {
@@ -800,7 +800,7 @@ public:
                     if(sr.is_header_done())
                         break;
                 }
-                BEAST_EXPECT(! m.body.read);
+                BEAST_EXPECT(! m.body().read);
                 tr.clear();
             }
             {
@@ -814,7 +814,7 @@ public:
                     if(sr.is_header_done())
                         break;
                 }
-                BEAST_EXPECT(! m.body.read);
+                BEAST_EXPECT(! m.body().read);
                 tr.clear();
             }
         }
diff --git a/test/doc/http_examples.cpp b/test/doc/http_examples.cpp
index dfafefd3..7b82e493 100644
--- a/test/doc/http_examples.cpp
+++ b/test/doc/http_examples.cpp
@@ -78,7 +78,7 @@ public:
         try
         {
             read(ts, b, m);
-            return m.body == body;
+            return m.body() == body;
         }
         catch(std::exception const& e)
         {
@@ -109,7 +109,7 @@ public:
                 req.method_string("POST");
                 req.target("/");
                 req.insert(field::user_agent, "test");
-                req.body = "Hello, world!";
+                req.body() = "Hello, world!";
                 req.prepare_payload();
 
                 error_code ec;
@@ -142,7 +142,7 @@ public:
         req.method_string("POST");
         req.target("/");
         req.insert(field::user_agent, "test");
-        req.body = "Hello, world!";
+        req.body() = "Hello, world!";
         req.prepare_payload();
 
         test::stream ds{ios_}, dsr{ios_};
@@ -167,7 +167,7 @@ public:
             });
         BEAST_EXPECTS(! ec, ec.message());
         BEAST_EXPECT(equal_body<true>(
-            usr.str(), req.body));
+            usr.str(), req.body()));
     }
 
     void
@@ -273,7 +273,7 @@ public:
         void
         operator()(request<string_body>&& req)
         {
-            body = req.body;
+            body = req.body();
         }
     };
 
diff --git a/test/doc/http_snippets.cpp b/test/doc/http_snippets.cpp
index a4e9397f..781765fc 100644
--- a/test/doc/http_snippets.cpp
+++ b/test/doc/http_snippets.cpp
@@ -61,7 +61,7 @@ void fxx() {
     res.version = 11;   // HTTP/1.1
     res.result(status::ok);
     res.set(field::server, "Beast");
-    res.body = "Hello, world!";
+    res.body() = "Hello, world!";
     res.prepare_payload();
 
 //]
@@ -115,7 +115,7 @@ void fxx() {
     res.version = 11;
     res.result(status::ok);
     res.set(field::server, "Beast");
-    res.body = "Hello, world!";
+    res.body() = "Hello, world!";
 
     error_code ec;
     write(sock, res, ec);