diff --git a/configure.ac b/configure.ac
index 09a9ecbc7..04f4632a0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-# Copyright (C) 2008-2020, Laboratoire de Recherche et Développement
+# Copyright (C) 2008-2021, Laboratoire de Recherche et Développement
 # de l'Epita (LRDE).
 # Copyright (C) 2003-2007 Laboratoire d'Informatique de Paris 6
 # (LIP6), département Systèmes Répartis Coopératifs (SRC), Université
@@ -49,12 +49,12 @@ AM_SILENT_RULES([no])
 
 # Option to activate C++17
 AC_ARG_ENABLE([c++17],
-              [AC_HELP_STRING([--enable-c++17],
+              [AS_HELP_STRING([--enable-c++17],
                               [Compile in C++17 mode.])],
               [enable_17=$enableval], [enable_17=no])
 
 AC_ARG_ENABLE([doxygen],
-              [AC_HELP_STRING([--enable-doxygen]),
+              [AS_HELP_STRING([--enable-doxygen]),
   [enable generation of Doxygen documentation (requires Doxygen)])],
   [enable_doxygen=$enableval], [enable_doxygen=no])
 AM_CONDITIONAL([ENABLE_DOXYGEN], [test "x${enable_doxygen:-no}" = xyes])
@@ -62,7 +62,7 @@ AM_CONDITIONAL([ENABLE_DOXYGEN], [test "x${enable_doxygen:-no}" = xyes])
 # Option to indicate the maximal number of acceptance marks
 AC_COMPUTE_INT([default_max_accsets], [8*sizeof(unsigned)])
 AC_ARG_ENABLE([max-accsets],
-              [AC_HELP_STRING([--enable-max-accsets=N],
+              [AS_HELP_STRING([--enable-max-accsets=N],
                               [Support up to N acceptance sets])],
               [enable_max_accsets=$enableval],
               [enable_max_accsets=$default_max_accsets])
@@ -71,7 +71,7 @@ then
   AC_DEFINE_UNQUOTED([MAX_ACCSETS], [$enable_max_accsets],
     [The maximal number of acceptance sets supported (also known as acceptance marks)])
 else
-  AC_ERROR([The argument of --enable-max-accsets must be a multiple of $default_max_accsets])
+  AC_MSG_ERROR([The argument of --enable-max-accsets must be a multiple of $default_max_accsets])
 fi
 
 # Activate C11 for gnulib tests
@@ -125,7 +125,7 @@ if test x"${enable_17}" = xyes; then
     ${stdpass-false} && break
   done
   if ! "${stdpass-false}"; then
-    AC_ERROR([unable to turn on C++17 mode with this compiler])
+    AC_MSG_ERROR([unable to turn on C++17 mode with this compiler])
   fi
 else
   for f in -std=c++14 '-std=c++14 -stdlib=libc++' -std=c++1y
@@ -135,7 +135,7 @@ else
     ${stdpass-false} && break
   done
   if ! "${stdpass-false}"; then
-    AC_ERROR([unable to turn on C++14 mode with this compiler])
+    AC_MSG_ERROR([unable to turn on C++14 mode with this compiler])
   fi
 fi
 
@@ -151,7 +151,7 @@ LTDL_INIT([subproject convenience])
 AX_BSYMBOLIC
 
 AC_ARG_ENABLE([python],
-              [AC_HELP_STRING([--disable-python],
+              [AS_HELP_STRING([--disable-python],
                               [do not compile Python bindings])],
               [], [enable_python=yes])
 
diff --git a/m4/debug.m4 b/m4/debug.m4
index 50bf5f3cb..a30a802f9 100644
--- a/m4/debug.m4
+++ b/m4/debug.m4
@@ -1,6 +1,6 @@
 AC_DEFUN([adl_ENABLE_DEBUG],
  [AC_ARG_ENABLE([debug],
-  [AC_HELP_STRING([--enable-debug],[enable debugging symbols])])
+  [AS_HELP_STRING([--enable-debug],[enable debugging symbols])])
   case "${enable_debug}" in
     yes)
       AC_DEFINE([DEBUG],1,[Define if you want debugging code.])
diff --git a/m4/devel.m4 b/m4/devel.m4
index 2cbfff661..07f7273ef 100644
--- a/m4/devel.m4
+++ b/m4/devel.m4
@@ -1,6 +1,6 @@
 AC_DEFUN([adl_ENABLE_DEVEL],
 [AC_ARG_ENABLE([devel],
-	       [AC_HELP_STRING([--enable-devel],
+	       [AS_HELP_STRING([--enable-devel],
 			       [turn on useful developer options])])
 
  # Turn on devel options for development version, unless
@@ -31,7 +31,7 @@ AC_DEFUN([adl_ENABLE_DEVEL],
 
 AC_DEFUN([adl_ENABLE_GLIBCXX_DEBUG],
 [AC_ARG_ENABLE([glibcxx-debug],
-  [AC_HELP_STRING([--enable-glibcxx-debug],
+  [AS_HELP_STRING([--enable-glibcxx-debug],
     [turn on use the libstdc++ debug mode (see README)])])
 if test x$enable_glibcxx_debug = xyes; then
   CPPFLAGS="$CPPFLAGS -D_GLIBCXX_DEBUG"
diff --git a/m4/gccoptim.m4 b/m4/gccoptim.m4
index beab5ba84..e731435e3 100644
--- a/m4/gccoptim.m4
+++ b/m4/gccoptim.m4
@@ -1,7 +1,7 @@
 dnl  Adapted from Akim Demaille <akim@epita.fr> ad_GCC_WARNINGS.
 AC_DEFUN([ad_GCC_OPTIM],
 [AC_ARG_ENABLE([optimizations],
- [AC_HELP_STRING([--disable-optimizations],
+ [AS_HELP_STRING([--disable-optimizations],
   [turn off aggressive optimizations])])
  if test -n "$GCC" && test "${enable_optimizations-yes}" = "yes"; then
   AC_CACHE_CHECK([for gcc optimization options], ac_cv_prog_gcc_opt_flags,
diff --git a/m4/ndebug.m4 b/m4/ndebug.m4
index 076f40aac..91f6cf31f 100644
--- a/m4/ndebug.m4
+++ b/m4/ndebug.m4
@@ -1,6 +1,6 @@
 AC_DEFUN([adl_NDEBUG],
  [AC_ARG_ENABLE([assert],
-  [AC_HELP_STRING([--enable-assert], [turn on assertions])])
+  [AS_HELP_STRING([--enable-assert], [turn on assertions])])
   if test "$enable_assert" != yes; then
     CPPFLAGS="$CPPFLAGS -DNDEBUG"
   fi])