--- configure.ac.orig	2020-11-11 16:11:31 UTC
+++ configure.ac
@@ -1,7 +1,8 @@ AC_INIT(libneurosim, 1.2.0, [https://github.com/INCF/l
 dnl Process this file with autoconf to produce configure.
 AC_INIT(libneurosim, 1.2.0, [https://github.com/INCF/libneurosim/issues])
-AM_INIT_AUTOMAKE
-AM_CONFIG_HEADER([config.h])
+AM_INIT_AUTOMAKE([subdir-objects])
+AC_CONFIG_HEADERS([config.h])
+AC_CONFIG_MACRO_DIRS([m4])
 AM_MAINTAINER_MODE
 
 # Obtain host system type
@@ -203,21 +204,10 @@ LDFLAGS=
 NS_SET_LDFLAGS
 LDFLAGS=
 
-LT_PATH_LD
 LT_CONFIG_LTDL_DIR([libltdl])
-_LTDL_CONVENIENCE                 ## put libltdl into a convenience library
 LT_INIT([dlopen])                 ## use libtool
-m4_pattern_allow([LT_LIBEXT])     ## supress false positive message by autoconf
+LTDL_INIT([recursive])
 
-if test "x$BUILD_SHARED" != xno ; then
-  if test "x$LIBLTDL" != x ; then
-    AC_DEFINE(HAVE_LIBLTDL, 1, [Havel libltdl, can load dynamic modules])
-  fi
-fi
-
-AC_CONFIG_SUBDIRS(libltdl)        ## also configure subdir containing libltdl
-AC_PROG_LIBTOOL
-
 #-- Set the language to C++
 AC_LANG_CPLUSPLUS
 
@@ -237,15 +227,13 @@ AC_SUBST(PYTHON_INCLUDE)
 AC_SUBST(MPI_LIBS)
 AC_SUBST(MPI_INCLUDE)
 AC_SUBST(PYTHON_INCLUDE)
-AC_SUBST(INCLTDL)
-AC_SUBST(LIBLTDL)
-AC_SUBST(HAVE_LIBLTDL)
 AC_SUBST(HAVE_MPI)
 AC_SUBST(NEUROSIM_HAVE_MPI)
 AC_SUBST(LIBADD_DL)
 
 AC_CONFIG_FILES([
   Makefile
+  libltdl/Makefile
   neurosim/Makefile
   neurosim/config.h
   neurosim/version.h