diff --git a/devel/boost-libs/Makefile b/devel/boost-libs/Makefile
index 2d327f1d3604..0ec1a3bdaf1e 100644
--- a/devel/boost-libs/Makefile
+++ b/devel/boost-libs/Makefile
@@ -1,58 +1,58 @@
 # Created by: Alexander Churanov <churanov.port.maintainer@gmail.com>
 
 PORTNAME=	boost-libs
-PORTREVISION=	3
+PORTREVISION=	4
 
 COMMENT=	Free portable C++ libraries (without Boost.Python)
 
 BROKEN_sparc64=	https://github.com/boostorg/context/commit/f2ef6326b6ed
 
 BUILD_DEPENDS+=	bjam:devel/boost-jam
 
 OPTIONS_DEFINE=		DEBUG OPTIMIZED_CFLAGS
 OPTIONS_MULTI=		LOCALE
 OPTIONS_MULTI_LOCALE=	ICONV ICU
 OPTIONS_DEFAULT=	ICONV ICU
 ICONV_DESC=		Boost.Locale with iconv encoding support
 ICU_DESC=		Boost.Regex/Locale with ICU unicode support
 
 ICONV_USES=		iconv
 ICONV_MAKE_ARGS=	-sICONV_PATH=${ICONV_PREFIX}
 ICONV_MAKE_ARGS_OFF=	boost.locale.iconv=off
 ICU_LIB_DEPENDS=	libicuuc.so:devel/icu
 ICU_MAKE_ARGS=		-sICU_PATH=${LOCALBASE}
 ICU_MAKE_ARGS_OFF=	boost.locale.icu=off
 
 .include "${.CURDIR}/../boost-all/common.mk"
 
 .include "${.CURDIR}/../boost-all/compiled.mk"
 
 MAKE_ARGS+=	--without-python
 MAKE_ARGS+=	${MAKE_ARGS_${CHOSEN_COMPILER_TYPE}}
 MAKE_ARGS_gcc=	xdll-path=${_GCC_RUNTIME}
 ALL_TARGET=	stage
 
 do-install:
 	@cd ${WRKSRC} && ${SETENV} ${MAKE_ENV} ${MAKE_CMD} \
 		${MAKE_ARGS:NDESTDIR=*:S,^--prefix=,&${STAGEDIR},} ${INSTALL_TARGET}
 	@${FIND} ${STAGEDIR}${PREFIX}/lib/cmake -type f -exec \
 		${REINPLACE_CMD} -i '' -e 's,${STAGEDIR},,' {} +
 # For some reasons BJAM forget about the links
 	@cd ${WRKSRC}/stage/ && ${FIND} lib -type l | ${PAX} -rw -p p ${STAGEDIR}${PREFIX}
 
 # display pkg-message
 post-install:
 	@${TOUCH} ${PKGMESSAGE}
 
 	@${CAT} ${PKG_MESSAGE_FILE_THREADS} >> ${PKGMESSAGE}
 	@${ECHO_CMD} >> ${PKGMESSAGE}
 
 	@${STRIP_CMD} ${STAGEDIR}${PREFIX}/lib/*.so
 
 	@${REINPLACE_CMD} \
 		-e "s|%%LOCALBASE%%|${LOCALBASE}|g" \
 		-e "s|%%PYTHON_INCLUDEDIR%%|${PYTHON_INCLUDEDIR}|g" \
 		-e "s|%%PYTHON_LIBDIR%%|${PYTHON_LIBDIR}|g" \
 		-e "s|%%PYTHON_VERSION%%|${PYTHON_VERSION}|g" ${PKGMESSAGE}
 
 .include <bsd.port.mk>
diff --git a/devel/boost-libs/files/patch-c++20-concepts b/devel/boost-libs/files/patch-c++20-concepts
new file mode 100644
index 000000000000..6ac8296abc84
--- /dev/null
+++ b/devel/boost-libs/files/patch-c++20-concepts
@@ -0,0 +1,69 @@
+From a707db8193b30b6cc4a3d10ee946f7f245e07097 Mon Sep 17 00:00:00 2001
+From: Christopher Kohlhoff <chris@kohlhoff.com>
+Date: Tue, 7 Apr 2020 11:18:31 +1000
+Subject: [PATCH] Support C++20 concept syntax.
+
+---
+ include/boost/asio/async_result.hpp  | 18 +++++++++++-------
+ include/boost/asio/detail/config.hpp | 10 +++++++---
+ 2 files changed, 18 insertions(+), 10 deletions(-)
+
+diff --git a/include/boost/asio/async_result.hpp b/include/boost/asio/async_result.hpp
+index 2f4b337d1..0eea0f471 100644
+--- boost/asio/async_result.hpp
++++ boost/asio/async_result.hpp
+@@ -66,9 +66,10 @@ BOOST_ASIO_CONCEPT completion_signature =
+ #define BOOST_ASIO_COMPLETION_SIGNATURE \
+   ::boost::asio::completion_signature
+ 
+-template <typename T, completion_signature Signature>
++template <typename T, typename Signature>
+ BOOST_ASIO_CONCEPT completion_handler_for =
+-  detail::is_completion_handler_for<T, Signature>::value;
++  detail::is_completion_signature<Signature>::value
++    && detail::is_completion_handler_for<T, Signature>::value;
+ 
+ #define BOOST_ASIO_COMPLETION_HANDLER_FOR(s) \
+   ::boost::asio::completion_handler_for<s>
+@@ -488,11 +489,14 @@ struct initiation_archetype
+ 
+ } // namespace detail
+ 
+-template <typename T, completion_signature Signature>
+-BOOST_ASIO_CONCEPT completion_token_for = requires(T&& t)
+-{
+-  async_initiate<T, Signature>(detail::initiation_archetype<Signature>{}, t);
+-};
++template <typename T, typename Signature>
++BOOST_ASIO_CONCEPT completion_token_for =
++  detail::is_completion_signature<Signature>::value
++  &&
++  requires(T&& t)
++  {
++    async_initiate<T, Signature>(detail::initiation_archetype<Signature>{}, t);
++  };
+ 
+ #define BOOST_ASIO_COMPLETION_TOKEN_FOR(s) \
+   ::boost::asio::completion_token_for<s>
+diff --git a/include/boost/asio/detail/config.hpp b/include/boost/asio/detail/config.hpp
+index 27d1d6753..6b85cccea 100644
+--- boost/asio/detail/config.hpp
++++ boost/asio/detail/config.hpp
+@@ -343,10 +343,14 @@
+ // Support concepts on compilers known to allow them.
+ #if !defined(BOOST_ASIO_HAS_CONCEPTS)
+ # if !defined(BOOST_ASIO_DISABLE_CONCEPTS)
+-#  if __cpp_concepts
++#  if defined(__cpp_concepts)
+ #   define BOOST_ASIO_HAS_CONCEPTS 1
+-#   define BOOST_ASIO_CONCEPT concept bool
+-#  endif // __cpp_concepts
++#   if (__cpp_concepts >= 201707)
++#    define BOOST_ASIO_CONCEPT concept
++#   else // (__cpp_concepts >= 201707)
++#    define BOOST_ASIO_CONCEPT concept bool
++#   endif // (__cpp_concepts >= 201707)
++#  endif // defined(__cpp_concepts)
+ # endif // !defined(BOOST_ASIO_DISABLE_CONCEPTS)
+ #endif // !defined(BOOST_ASIO_HAS_CONCEPTS)
+