diff --git a/m4/ac_python_devel.m4 b/m4/ax_python_devel.m4
similarity index 61%
rename from m4/ac_python_devel.m4
rename to m4/ax_python_devel.m4
index 545c607..44dbd83 100644
--- a/m4/ac_python_devel.m4
+++ b/m4/ax_python_devel.m4
@@ -1,10 +1,10 @@
 # ===========================================================================
-#            http://autoconf-archive.cryp.to/ac_python_devel.html
+#     https://www.gnu.org/software/autoconf-archive/ax_python_devel.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AC_PYTHON_DEVEL([version])
+#   AX_PYTHON_DEVEL([version])
 #
 # DESCRIPTION
 #
@@ -12,8 +12,8 @@
 #   in your configure.ac.
 #
 #   This macro checks for Python and tries to get the include path to
-#   'Python.h'. It provides the $(PYTHON_CPPFLAGS) and $(PYTHON_LDFLAGS)
-#   output variables. It also exports $(PYTHON_EXTRA_LIBS) and
+#   'Python.h'. It provides the $(PYTHON_CPPFLAGS) and $(PYTHON_LIBS) output
+#   variables. It also exports $(PYTHON_EXTRA_LIBS) and
 #   $(PYTHON_EXTRA_LDFLAGS) for embedding Python in your code.
 #
 #   You can search for some particular version of Python by passing a
@@ -31,18 +31,15 @@
 #   If you need to use this macro for an older Python version, please
 #   contact the authors. We're always open for feedback.
 #
-# LAST MODIFICATION
+# LICENSE
 #
-#   2008-04-12
-#
-# COPYLEFT
-#
-#   Copyright (c) 2008 Sebastian Huber <sebastian-huber@web.de>
-#   Copyright (c) 2008 Alan W. Irwin <irwin@beluga.phys.uvic.ca>
-#   Copyright (c) 2008 Rafael Laboissiere <rafael@laboissiere.net>
-#   Copyright (c) 2008 Andrew Collier <colliera@ukzn.ac.za>
-#   Copyright (c) 2008 Matteo Settenvini <matteo@member.fsf.org>
-#   Copyright (c) 2008 Horst Knorr <hk_classes@knoda.org>
+#   Copyright (c) 2009 Sebastian Huber <sebastian-huber@web.de>
+#   Copyright (c) 2009 Alan W. Irwin
+#   Copyright (c) 2009 Rafael Laboissiere <rafael@laboissiere.net>
+#   Copyright (c) 2009 Andrew Collier
+#   Copyright (c) 2009 Matteo Settenvini <matteo@member.fsf.org>
+#   Copyright (c) 2009 Horst Knorr <hk_classes@knoda.org>
+#   Copyright (c) 2013 Daniel Mullner <muellner@math.stanford.edu>
 #
 #   This program is free software: you can redistribute it and/or modify it
 #   under the terms of the GNU General Public License as published by the
@@ -55,7 +52,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright owner
 #   gives unlimited permission to copy, distribute and modify the configure
@@ -66,11 +63,14 @@
 #   all other use of the material that constitutes the Autoconf Macro.
 #
 #   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Macro Archive. When you make and
-#   distribute a modified version of the Autoconf Macro, you may extend this
-#   special exception to the GPL to apply to your modified version as well.
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
 
-AC_DEFUN([AC_PYTHON_DEVEL],[
+#serial 21
+
+AU_ALIAS([AC_PYTHON_DEVEL], [AX_PYTHON_DEVEL])
+AC_DEFUN([AX_PYTHON_DEVEL],[
 	#
 	# Allow the use of a (user set) custom python version
 	#
@@ -90,8 +90,8 @@
 	#
 	AC_MSG_CHECKING([for a version of Python >= '2.1.0'])
 	ac_supports_python_ver=`$PYTHON -c "import sys; \
-		ver = sys.version.split()[[0]]; \
-		print(ver >= '2.1.0')"`
+		ver = sys.version.split ()[[0]]; \
+		print (ver >= '2.1.0')"`
 	if test "$ac_supports_python_ver" != "True"; then
 		if test -z "$PYTHON_NOVERSIONCHECK"; then
 			AC_MSG_RESULT([no])
@@ -99,7 +99,7 @@
 This version of the AC@&t@_PYTHON_DEVEL macro
 doesn't work properly with versions of Python before
 2.1.0. You may need to re-run configure, setting the
-variables PYTHON_CPPFLAGS, PYTHON_LDFLAGS, PYTHON_SITE_PKG,
+variables PYTHON_CPPFLAGS, PYTHON_LIBS, PYTHON_SITE_PKG,
 PYTHON_EXTRA_LIBS and PYTHON_EXTRA_LDFLAGS by hand.
 Moreover, to disable this check, set PYTHON_NOVERSIONCHECK
 to something else than an empty string.
@@ -117,10 +117,10 @@
 	if test -n "$1"; then
 		AC_MSG_CHECKING([for a version of Python $1])
 		ac_supports_python_ver=`$PYTHON -c "import sys; \
-			ver = sys.version.split()[[0]]; \
-			print(ver >= '2.1.0')"`
+			ver = sys.version.split ()[[0]]; \
+			print (ver $1)"`
 		if test "$ac_supports_python_ver" = "True"; then
-	   	   AC_MSG_RESULT([yes])
+		   AC_MSG_RESULT([yes])
 		else
 			AC_MSG_RESULT([no])
 			AC_MSG_ERROR([this package requires Python $1.
@@ -137,7 +137,7 @@
 	#
 	AC_MSG_CHECKING([for the distutils Python package])
 	ac_distutils_result=`$PYTHON -c "import distutils" 2>&1`
-	if test -z "$ac_distutils_result"; then
+	if test $? -eq 0; then
 		AC_MSG_RESULT([yes])
 	else
 		AC_MSG_RESULT([no])
@@ -151,14 +151,17 @@
 	# Check for Python include path
 	#
 	AC_MSG_CHECKING([for Python include path])
-	if type $PYTHON-config; then
-		PYTHON_CPPFLAGS=`$PYTHON-config --includes`
-	fi
 	if test -z "$PYTHON_CPPFLAGS"; then
 		python_path=`$PYTHON -c "import distutils.sysconfig; \
-			print(distutils.sysconfig.get_python_inc());"`
+			print (distutils.sysconfig.get_python_inc ());"`
+		plat_python_path=`$PYTHON -c "import distutils.sysconfig; \
+			print (distutils.sysconfig.get_python_inc (plat_specific=1));"`
 		if test -n "${python_path}"; then
-		   	python_path="-I$python_path"
+			if test "${plat_python_path}" != "${python_path}"; then
+				python_path="-I$python_path -I$plat_python_path"
+			else
+				python_path="-I$python_path"
+			fi
 		fi
 		PYTHON_CPPFLAGS=$python_path
 	fi
@@ -169,29 +172,80 @@
 	# Check for Python library path
 	#
 	AC_MSG_CHECKING([for Python library path])
-	if type $PYTHON-config; then
-		PYTHON_LDFLAGS=`$PYTHON-config --ldflags`
-	fi
-	if test -z "$PYTHON_LDFLAGS"; then
+	if test -z "$PYTHON_LIBS"; then
 		# (makes two attempts to ensure we've got a version number
 		# from the interpreter)
-		py_version=`$PYTHON -c "from distutils.sysconfig import *; \
-			print(' '.join(get_config_vars('VERSION')))"`
-		if test "$py_version" = "[None]"; then
+		ac_python_version=`cat<<EOD | $PYTHON -
+
+# join all versioning strings, on some systems
+# major/minor numbers could be in different list elements
+from distutils.sysconfig import *
+e = get_config_var('VERSION')
+if e is not None:
+	print(e)
+EOD`
+
+		if test -z "$ac_python_version"; then
 			if test -n "$PYTHON_VERSION"; then
-				py_version=$PYTHON_VERSION
+				ac_python_version=$PYTHON_VERSION
 			else
-				py_version=`$PYTHON -c "import sys; \
-					print(sys.version[[:3]]")`
+				ac_python_version=`$PYTHON -c "import sys; \
+					print (sys.version[[:3]])"`
 			fi
 		fi
 
-		PYTHON_LDFLAGS=`$PYTHON -c "from distutils.sysconfig import *; \
-			print('-L' + get_python_lib(0,1) + \
-			' -lpython');"`$py_version
+		# Make the versioning information available to the compiler
+		AC_DEFINE_UNQUOTED([HAVE_PYTHON], ["$ac_python_version"],
+                                   [If available, contains the Python version number currently in use.])
+
+		# First, the library directory:
+		ac_python_libdir=`cat<<EOD | $PYTHON -
+
+# There should be only one
+import distutils.sysconfig
+e = distutils.sysconfig.get_config_var('LIBDIR')
+if e is not None:
+	print (e)
+EOD`
+
+		# Now, for the library:
+		ac_python_library=`cat<<EOD | $PYTHON -
+
+import distutils.sysconfig
+c = distutils.sysconfig.get_config_vars()
+if 'LDVERSION' in c:
+	print ('python'+c[['LDVERSION']])
+else:
+	print ('python'+c[['VERSION']])
+EOD`
+
+		# This small piece shamelessly adapted from PostgreSQL python macro;
+		# credits goes to momjian, I think. I'd like to put the right name
+		# in the credits, if someone can point me in the right direction... ?
+		#
+		if test -n "$ac_python_libdir" -a -n "$ac_python_library"
+		then
+			# use the official shared library
+			ac_python_library=`echo "$ac_python_library" | sed "s/^lib//"`
+			PYTHON_LIBS="-L$ac_python_libdir -l$ac_python_library"
+		else
+			# old way: use libpython from python_configdir
+			ac_python_libdir=`$PYTHON -c \
+			  "from distutils.sysconfig import get_python_lib as f; \
+			  import os; \
+			  print (os.path.join(f(plat_specific=1, standard_lib=1), 'config'));"`
+			PYTHON_LIBS="-L$ac_python_libdir -lpython$ac_python_version"
+		fi
+
+		if test -z "PYTHON_LIBS"; then
+			AC_MSG_ERROR([
+  Cannot determine location of your Python DSO. Please check it was installed with
+  dynamic libraries enabled, or try setting PYTHON_LIBS by hand.
+			])
+		fi
 	fi
-	AC_MSG_RESULT([$PYTHON_LDFLAGS])
-	AC_SUBST([PYTHON_LDFLAGS])
+	AC_MSG_RESULT([$PYTHON_LIBS])
+	AC_SUBST([PYTHON_LIBS])
 
 	#
 	# Check for site packages
@@ -199,7 +253,7 @@
 	AC_MSG_CHECKING([for Python site-packages path])
 	if test -z "$PYTHON_SITE_PKG"; then
 		PYTHON_SITE_PKG=`$PYTHON -c "import distutils.sysconfig; \
-		        print(distutils.sysconfig.get_python_lib(0,0))"`
+			print (distutils.sysconfig.get_python_lib(0,0));"`
 	fi
 	AC_MSG_RESULT([$PYTHON_SITE_PKG])
 	AC_SUBST([PYTHON_SITE_PKG])
@@ -211,7 +265,7 @@
 	if test -z "$PYTHON_EXTRA_LIBS"; then
 	   PYTHON_EXTRA_LIBS=`$PYTHON -c "import distutils.sysconfig; \
                 conf = distutils.sysconfig.get_config_var; \
-                print(conf('LOCALMODLIBS'), conf('LIBS'))"`
+                print (conf('LIBS') + ' ' + conf('SYSLIBS'))"`
 	fi
 	AC_MSG_RESULT([$PYTHON_EXTRA_LIBS])
 	AC_SUBST(PYTHON_EXTRA_LIBS)
@@ -223,7 +277,7 @@
 	if test -z "$PYTHON_EXTRA_LDFLAGS"; then
 		PYTHON_EXTRA_LDFLAGS=`$PYTHON -c "import distutils.sysconfig; \
 			conf = distutils.sysconfig.get_config_var; \
-			print(conf('LINKFORSHARED'))"`
+			print (conf('LINKFORSHARED'))"`
 	fi
 	AC_MSG_RESULT([$PYTHON_EXTRA_LDFLAGS])
 	AC_SUBST(PYTHON_EXTRA_LDFLAGS)
@@ -232,24 +286,32 @@
 	# final check to see if everything compiles alright
 	#
 	AC_MSG_CHECKING([consistency of all components of python development environment])
-	AC_LANG_PUSH([C])
 	# save current global flags
-	LIBS="$ac_save_LIBS $PYTHON_LDFLAGS"
+	ac_save_LIBS="$LIBS"
+	ac_save_LDFLAGS="$LDFLAGS"
+	ac_save_CPPFLAGS="$CPPFLAGS"
+	LIBS="$ac_save_LIBS $PYTHON_LIBS $PYTHON_EXTRA_LIBS $PYTHON_EXTRA_LIBS"
+	LDFLAGS="$ac_save_LDFLAGS $PYTHON_EXTRA_LDFLAGS"
 	CPPFLAGS="$ac_save_CPPFLAGS $PYTHON_CPPFLAGS"
-	AC_TRY_LINK([
-		#include <Python.h>
-	],[
-		Py_Initialize();
-	],[pythonexists=yes],[pythonexists=no])
+	AC_LANG_PUSH([C])
+	AC_LINK_IFELSE([
+		AC_LANG_PROGRAM([[#include <Python.h>]],
+				[[Py_Initialize();]])
+		],[pythonexists=yes],[pythonexists=no])
+	AC_LANG_POP([C])
+	# turn back to default flags
+	CPPFLAGS="$ac_save_CPPFLAGS"
+	LIBS="$ac_save_LIBS"
+	LDFLAGS="$ac_save_LDFLAGS"
 
 	AC_MSG_RESULT([$pythonexists])
 
-        if test ! "$pythonexists" = "yes"; then
-	   AC_MSG_ERROR([
+        if test ! "x$pythonexists" = "xyes"; then
+	   AC_MSG_FAILURE([
   Could not link test program to Python. Maybe the main Python library has been
   installed in some non-standard library path. If so, pass it to configure,
-  via the LDFLAGS environment variable.
-  Example: ./configure LDFLAGS="-L/usr/non-standard-path/python/lib"
+  via the LIBS environment variable.
+  Example: ./configure LIBS="-L/usr/non-standard-path/python/lib"
   ============================================================================
    ERROR!
    You probably have to install the development version of the Python package
@@ -258,10 +320,6 @@
 	   ])
 	  PYTHON_VERSION=""
 	fi
-	AC_LANG_POP
-	# turn back to default flags
-	CPPFLAGS="$ac_save_CPPFLAGS"
-	LIBS="$ac_save_LIBS"
 
 	#
 	# all done!