diff --git a/configure.ac b/configure.ac
index 4e8099777..56e566ed6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -41,7 +41,8 @@ AC_PROG_LIBTOOL
 AC_PROG_MAKE_SET
 
 AC_LANG(C++)
-AX_CXX_COMPILE_STDCXX([17], [gnu], [mandatory], 201703)
+AX_CXX_COMPILE_STDCXX([20], [gnu], [optional], 202002)
+AX_CXX_COMPILE_STDCXX([2a], [gnu], [mandatory], 201709)
 
 
 dnl ***************************************************************************
@@ -2558,7 +2559,7 @@ RB_HELP_STRING([--with-included-boost[[[=shared]]]], [Use the boost sources from
 
 	boost_linkage="$withval"
 	boost_version="boost-${BOOST_VERSION_MIN}.${BOOST_VERSION_MIN_PATCH}"
-	boost_cxxflags="-std=gnu++17"
+	boost_cxxflags="-std=gnu++20"
 	bash tools/boostrap.sh $BTOOLSET $BOOST_BUILT_LIBS $boost_variant $withval multi $boost_version $boost_cxxflags
 	AS_IF([ test $? != 0 ],
 	[
diff --git a/tools/m4/ax_cxx_compile_stdcxx.m4 b/tools/m4/ax_cxx_compile_stdcxx.m4
index 9bc83430b..4005f9f3a 100644
--- a/tools/m4/ax_cxx_compile_stdcxx.m4
+++ b/tools/m4/ax_cxx_compile_stdcxx.m4
@@ -48,6 +48,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
   m4_if([$1], [11], [],
         [$1], [14], [],
         [$1], [17], [],
+        [$1], [2a], [],
         [$1], [20], [],
         [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl
   m4_if([$2], [], [],
@@ -157,6 +158,22 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17],
   _AX_CXX_COMPILE_STDCXX_testbody_new_in_14($1)
 )
 
+dnl  Test body for checking C++2a support
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_2a],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11($1)
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14($1)
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_17($1)
+)
+
+dnl  Test body for checking C++20 support
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_20],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11($1)
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14($1)
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_17($1)
+)
+
 
 dnl  Tests for new features in C++11
 
@@ -573,3 +590,15 @@ namespace cxx14
 #endif  // __cplusplus >= $1L
 
 ]])
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
+
+]])
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_2a], [[
+
+]])
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_20], [[
+
+]])