diff --git a/configure.ac b/configure.ac
index 8090448..3be6a8b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,390 +1,425 @@
 # configure.ac                                          -*- Autoconf -*-
 # Copyright (C) 2011, 2012 g10 Code GmbH
 #
 # This file is part of nPth.
 #
 # nPth is free software; you can redistribute it and/or modify it
 # under the terms of the GNU Lesser General Public License as
 # published by the Free Software Foundation; either version 2.1 of the
 # License, or (at your option) any later version.
 #
 # nPth is distributed in the hope that it will be useful, but WITHOUT
 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 # or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
 # Public License for more details.
 #
 # You should have received a copy of the GNU Lesser General Public
 # License along with this program; if not, see <http://www.gnu.org/licenses/>.
 
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.67])
 min_automake_version="1.14"
 
 # To build a release you need to create a tag with the version number
 # (git tag -s npth-n.m) and run "./autogen.sh --force".  Please bump
 # the version number immediately after the release and do another
 # commit and push so that the git magic is able to work.
 # See below for the LT versions.
 m4_define([mym4_package],[npth])
 m4_define([mym4_major], [1])
 m4_define([mym4_minor], [7])
 
 # To start a new development series, i.e a new major or minor number
 # you need to mark an arbitrary commit before the first beta release
 # with an annotated tag.  For example a 2.1 branch starts off with
 # the tag "foo-2.1-base".  This is used as the base for counting
 # beta numbers before the first release of a series.
 
 # Below is m4 magic to extract and compute the git revision number,
 # the decimalized short revision number, a beta version string and a
 # flag indicating a development version (mym4_isbeta).  Note that the
 # m4 processing is done by autoconf and not during the configure run.
 m4_define([mym4_verslist], m4_split(m4_esyscmd([./autogen.sh --find-version] \
                            mym4_package mym4_major mym4_minor),[:]))
 m4_define([mym4_isbeta],       m4_argn(2, mym4_verslist))
 m4_define([mym4_version],      m4_argn(4, mym4_verslist))
 m4_define([mym4_revision],     m4_argn(7, mym4_verslist))
 m4_define([mym4_revision_dec], m4_argn(8, mym4_verslist))
 m4_esyscmd([echo ]mym4_version[>VERSION])
 AC_INIT([mym4_package],[mym4_version], [https://bugs.gnupg.org])
 # LT Version numbers, remember to change them just *before* a release.
 #   (Code changed:			REVISION++)
 #   (Interfaces added/removed/changed:	CURRENT++, REVISION=0)
 #   (Interfaces added:			AGE++)
 #   (Interfaces removed:		AGE=0)
 #
 LIBNPTH_LT_CURRENT=1
 LIBNPTH_LT_AGE=1
 LIBNPTH_LT_REVISION=2
 ################################################
 
 AC_SUBST(LIBNPTH_LT_CURRENT)
 AC_SUBST(LIBNPTH_LT_AGE)
 AC_SUBST(LIBNPTH_LT_REVISION)
 
 VERSION_NUMBER=m4_esyscmd(printf "0x%02x%02x00" mym4_major mym4_minor)
 AC_SUBST(VERSION_NUMBER)
 
 # If the API is changed in an incompatible way: increment the next counter.
 NPTH_CONFIG_API_VERSION=1
 ##############################################
 
 AC_CONFIG_AUX_DIR([build-aux])
 AM_INIT_AUTOMAKE([serial-tests dist-bzip2 no-dist-gzip])
 AM_MAINTAINER_MODE
 AC_CONFIG_SRCDIR([src/npth.c])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CANONICAL_HOST
 AM_SILENT_RULES
 
 # Enable GNU extensions on systems that have them.
 AC_GNU_SOURCE
 
+# Taken from mpfr-4.0.1, then modified for LDADD_FOR_TESTS_KLUDGE
+dnl Under Linux, make sure that the old dtags are used if LD_LIBRARY_PATH
+dnl is defined. The issue is that with the new dtags, LD_LIBRARY_PATH has
+dnl the precedence over the run path, so that if a compatible MPFR library
+dnl is installed in some directory from $LD_LIBRARY_PATH, then the tested
+dnl MPFR library will be this library instead of the MPFR library from the
+dnl build tree. Other OS with the same issue might be added later.
+dnl
+dnl References:
+dnl   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=859732
+dnl   http://lists.gnu.org/archive/html/libtool/2017-05/msg00000.html
+dnl
+dnl We need to check whether --disable-new-dtags is supported as alternate
+dnl linkers may be used (e.g., with tcc: CC=tcc LD=tcc).
+dnl
+case $host in
+  *-*-linux*)
+    if test -n "$LD_LIBRARY_PATH"; then
+      saved_LDFLAGS="$LDFLAGS"
+      LDADD_FOR_TESTS_KLUDGE="-Wl,--disable-new-dtags"
+      LDFLAGS="$LDFLAGS $LDADD_FOR_TESTS_KLUDGE"
+      AC_MSG_CHECKING(whether --disable-new-dtags is supported by the linker)
+      AC_LINK_IFELSE([AC_LANG_SOURCE([[
+int main (void) { return 0; }
+      ]])],
+      [AC_MSG_RESULT(yes (use it since LD_LIBRARY_PATH is set))],
+      [AC_MSG_RESULT(no)
+       LDADD_FOR_TESTS_KLUDGE=""
+      ])
+      LDFLAGS="$saved_LDFLAGS"
+    fi
+    ;;
+esac
+AC_SUBST([LDADD_FOR_TESTS_KLUDGE])
+
 AH_VERBATIM([_REENTRANT],
 [#ifndef _REENTRANT
 # define _REENTRANT 1
 #endif])
 
 # Checks for programs.
 AC_PROG_CC
 
 run_tests="yes"
 AC_ARG_ENABLE(tests,
   AC_HELP_STRING([--disable-tests], [disable tests]),
          run_tests=$enableval)
 AM_CONDITIONAL(RUN_TESTS, test "$run_tests" = "yes")
 
 
 # Don't default to build static libs.
 LT_PREREQ([2.2.6])
 LT_INIT([win32-dll disable-static])
 LT_LANG([Windows Resource])
 
 
 # For now we hardcode the use of version scripts.  It would be better
 # to write a test for this or even implement this within libtool.
 have_ld_version_script=no
 case "${host}" in
     *-*-linux*)
         have_ld_version_script=yes
         ;;
     *-*-gnu*)
         have_ld_version_script=yes
         ;;
     *-apple-darwin*)
         AC_SEARCH_LIBS([dispatch_semaphore_create],[dispatch],
         [AC_DEFINE([HAVE_LIB_DISPATCH],1,[Defined if we have libdispatch])])
         ;;
     *-*-aix*)
         have_fork_unsafe_semaphore=yes
         ;;
     *-*-dragonfly*|*-*-freebsd*|*-*-netbsd*|*-*-hpux*)
         LIBS="-lpthread $LIBS"
         AC_SEARCH_LIBS([sem_init],[rt])
         ;;
 esac
 
 AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$have_ld_version_script" = "yes")
 if test "$have_fork_unsafe_semaphore" = yes; then
    AC_DEFINE(HAVE_FORK_UNSAFE_SEMAPHORE, 1, [Defined if we have fork-unsafe semaphore])
 fi
 
 # Set some default values
 config_libs="-lnpth $LIBS"
 have_w32_system=no
 have_w32ce_system=no
 have_w64_system=no
 
 # Define OS macros
 case "${host}" in
     x86_64-*mingw32*)
         have_w64_system=yes
         ;;
     *-mingw32ce*)
         have_w32ce_system=yes
         ;;
 esac
 case "${host}" in
     *-mingw32ce*|*-mingw32*)
         have_w32_system=yes
         ;;
     *)
         ;;
 esac
 
 if test "$have_w32_system" = yes; then
    AC_DEFINE(HAVE_W32_SYSTEM,1,
              [Defined if we run on any kind of W32 API based system])
 fi
 AM_CONDITIONAL(HAVE_W32_SYSTEM, test "$have_w32_system" = yes)
 
 if test "$have_w64_system" = yes; then
    AC_DEFINE(HAVE_W64_SYSTEM,1,
              [Defined if we run on a 64 bit W32 API based system])
 fi
 AM_CONDITIONAL(HAVE_W64_SYSTEM, test "$have_w64_system" = yes)
 
 #
 # Generate values for the DLL version info
 #
 if test "$have_w32_system" = yes; then
     BUILD_ISODATE=`date --iso-8601`
     changequote(,)dnl
     BUILD_FILEVERSION=`echo "$VERSION" | sed 's/\([0-9.]*\).*/\1./;s/\./,/g'`
     changequote([,])dnl
     BUILD_FILEVERSION="${BUILD_FILEVERSION}git_revision_dec"
 fi
 AC_SUBST(BUILD_ISODATE)
 AC_SUBST(BUILD_FILEVERSION)
 AC_ARG_ENABLE([build-timestamp],
   AC_HELP_STRING([--enable-build-timestamp],
                  [set an explicit build timestamp for reproducibility.
                   (default is the current time in ISO-8601 format)]),
      [if test "$enableval" = "yes"; then
         BUILD_TIMESTAMP=`date -u +%Y-%m-%dT%H:%M+0000 2>/dev/null || date`
       else
         BUILD_TIMESTAMP="$enableval"
       fi],
      [BUILD_TIMESTAMP="<none>"])
 AC_SUBST(BUILD_TIMESTAMP)
 AC_DEFINE_UNQUOTED(BUILD_TIMESTAMP, "$BUILD_TIMESTAMP",
                    [The time this package was configured for a build])
 
 
 #
 # Checks for header files.
 #
 # fixme: For what do we need the sys/socket test?
 AC_CHECK_HEADERS([sys/socket.h sys/select.h unistd.h sys/time.h time.h \
                   signal.h])
 INSERT_SYS_SELECT_H=
 if test x"$ac_cv_header_sys_select_h" = xyes; then
   INSERT_SYS_SELECT_H="include <sys/select.h>"
 fi
 AC_SUBST(INSERT_SYS_SELECT_H)
 
 if test x"$ac_cv_header_sys_time_h" = xyes; then
   INSERT_SYS_TIME_H="include <sys/time.h>"
 fi
 AC_SUBST(INSERT_SYS_TIME_H)
 
 if test x"$ac_cv_header_time_h" = xyes; then
   INSERT_TIME_H="include <time.h>"
 fi
 AC_SUBST(INSERT_TIME_H)
 
 if test x"$ac_cv_header_signal_h" = xyes; then
   INSERT_SIGNAL_H="include <signal.h>"
 fi
 AC_SUBST(INSERT_SIGNAL_H)
 
 
 # Some systems lack socklen_t - provide a replacement.
 gl_TYPE_SOCKLEN_T
 case "${host}" in
   *-*-mingw32*)
     # socklen_t may or may not be defined depending on what headers
     # are included.  To be safe we use int as this is the actual type.
     INSERT_SOCKLEN_T="define _npth_socklen_t int"
     ;;
   *)
     if test ".$gl_cv_socklen_t_equiv" = "."; then
       INSERT_SOCKLEN_T="define _npth_socklen_t socklen_t"
     else
       INSERT_SOCKLEN_T="define _npth_socklen_t ${gl_cv_socklen_t_equiv}"
     fi
 esac
 AC_SUBST(INSERT_SOCKLEN_T)
 
 
 #
 # Checks for typedefs, structures, and compiler characteristics.
 #
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_TYPE_SSIZE_T
 
 
 #
 # Checks for libraries and functions.
 #
 #   We test for pthread_detach because glibc 2.22 includes
 #   pthread_create but not pthread_detach.
 if test "$have_w32_system" = no; then
   AC_SEARCH_LIBS([pthread_detach],[pthread])
   case "x$ac_cv_search_pthread_detach" in
     xno)
       have_pthread=no
       ;;
     xnone\ required)
       have_pthread=yes
       ;;
     *)
       have_pthread=yes
       config_libs="$config_libs $ac_cv_search_pthread_detach"
       ;;
   esac
   if test "$have_pthread" != no; then
     AC_DEFINE(HAVE_PTHREAD,1,[Define if we have pthread.])
     AC_CHECK_TYPE([pthread_rwlock_t])
     AC_CHECK_FUNCS([pthread_tryjoin_np pthread_setname_np pthread_getname_np])
     AC_CHECK_FUNCS([pthread_mutex_timedlock])
     AC_CHECK_FUNCS([pthread_rwlock_rdlock pthread_rwlock_wrlock])
     AC_CHECK_FUNCS([pthread_rwlock_timedrdlock pthread_rwlock_timedwrlock])
     AC_CHECK_FUNCS([pthread_rwlock_tryrdlock pthread_rwlock_trywrlock])
     AC_CHECK_FUNCS([pthread_atfork])
   fi
 fi
 
 INSERT_NO_RWLOCK="undef _NPTH_NO_RWLOCK"
 if test x"$ac_cv_type_pthread_rwlock_t" = xno; then
   INSERT_NO_RWLOCK="define _NPTH_NO_RWLOCK 1"
 fi
 AC_SUBST(INSERT_NO_RWLOCK)
 
 case "${host}" in
     *-*-linux*|*-*-gnu*)
         INSERT_EXPOSE_RWLOCK_API="define _NPTH_EXPOSE_RWLOCK_API (defined(__USE_UNIX98) || defined(__USE_XOPEN2K))"
         ;;
     *)
         INSERT_EXPOSE_RWLOCK_API="define _NPTH_EXPOSE_RWLOCK_API 1"
         ;;
 esac
 AC_SUBST(INSERT_EXPOSE_RWLOCK_API)
 
 AC_CHECK_FUNCS([select pselect gettimeofday])
 
 npth_LIBSOCKET
 config_libs="$config_libs $LIBSOCKET"
 
 # Save and restore LIBS so e.g., -lrt, isn't added to it.  Otherwise, *all*
 # programs in the package would end up linked with that potentially-shared
 # library, inducing unnecessary run-time overhead.
 LIB_CLOCK_GETTIME=
 AC_SUBST([LIB_CLOCK_GETTIME])
 gl_saved_libs=$LIBS
 AC_SEARCH_LIBS([clock_gettime], [rt posix4],
                [if test "$ac_cv_search_clock_gettime" != "none required"; then
                   LIB_CLOCK_GETTIME=$ac_cv_search_clock_gettime
                   config_libs="$config_libs $LIB_CLOCK_GETTIME"
                 fi
                 AC_DEFINE([HAVE_CLOCK_GETTIME],1,
                   [Define to 1 if you have the `clock_gettime' function.])
                 ])
 LIBS=$gl_saved_libs
 
 
 #
 # Set NETLIBS
 #
 if test "$have_w32ce_system" = yes; then
    NETLIBS="-lws2 $NETLIBS"
 elif test "$have_w32_system" = yes; then
    NETLIBS="-lws2_32 $NETLIBS"
 fi
 AC_SUBST(NETLIBS)
 
 
 #
 # Substitutions to set generated files in a Emacs buffer to read-only.
 #
 AC_SUBST(emacs_local_vars_begin, [['Local][ ][Variables:']])
 AC_SUBST(emacs_local_vars_read_only, ['buffer-read-only: t'])
 AC_SUBST(emacs_local_vars_end, ['End:'])
 
 
 #
 # Substitution used for npth-config
 #
 NPTH_CONFIG_LIBS="$config_libs"
 NPTH_CONFIG_CFLAGS=""
 NPTH_CONFIG_HOST="$host"
 AC_SUBST(NPTH_CONFIG_API_VERSION)
 AC_SUBST(NPTH_CONFIG_LIBS)
 AC_SUBST(NPTH_CONFIG_CFLAGS)
 AC_SUBST(NPTH_CONFIG_HOST)
 
 #
 # Last check.
 #
 die=no
 if test "$have_w32_system" = no; then
   if test "$have_pthread" = "no"; then
      die=yes
      AC_MSG_NOTICE([[
 ***
 *** You need Pthread to build this program.
 *** Normally, this library comes with your system.  On Windows, you can use:
 ***   http://sourceware.org/pthreads-win32/
 ***]])
   fi
 fi
 
 if test "$die" = "yes"; then
     AC_MSG_ERROR([[
 ***
 *** Required libraries not found. Please consult the above messages
 *** and install them before running configure again.
 ***]])
 fi
 
 #
 # Write output
 #
 AC_CONFIG_FILES([Makefile
 npth.pc
 src/npth.h
 src/Makefile
 w32/Makefile
 tests/Makefile])
 AC_CONFIG_FILES(npth-config, chmod +x npth-config)
 AC_OUTPUT
 
 echo "
         $PACKAGE_NAME v$PACKAGE_VERSION prepared for make
 
         Revision: mym4_revision  (mym4_revision_dec)
         Platform: $host
 "
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 4329a00..4b45e40 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,36 +1,37 @@
 # Makefile.am - Makefile for NPTH tests.
 # Copyright (C) 2011 g10 Code GmbH
 #
 # This file is part of nPth.
 #
 # nPth is free software; you can redistribute it and/or modify it
 # under the terms of the GNU Lesser General Public License as
 # published by the Free Software Foundation; either version 2.1 of the
 # License, or (at your option) any later version.
 #
 # nPth is distributed in the hope that it will be useful, but WITHOUT
 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 # or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
 # Public License for more details.
 #
 # You should have received a copy of the GNU Lesser General Public
 # License along with this program; if not, see <http://www.gnu.org/licenses/>.
 
 ## Process this file with automake to produce Makefile.in
 
 TESTS = t-mutex t-thread
 
 if HAVE_W32_SYSTEM
 AM_CPPFLAGS = -I$(top_srcdir)/w32
 LDADD = ../w32/libnpth.la $(LIB_CLOCK_GETTIME)
 else
 AM_CPPFLAGS = -I../src
 LDADD = ../src/libnpth.la $(LIBSOCKET) $(LIB_CLOCK_GETTIME)
 TESTS += t-fork
 endif
 
+LDADD += @LDADD_FOR_TESTS_KLUDGE@
 AM_LDFLAGS = -no-install
 
 noinst_HEADERS = t-support.h
 
 noinst_PROGRAMS = $(TESTS)