diff --git a/npth.m4 b/npth.m4
index d36c39d..f5a73db 100644
--- a/npth.m4
+++ b/npth.m4
@@ -1,122 +1,134 @@
 # npth.m4 - autoconf macro to detect NPTH.
 # Copyright (C) 2002, 2003, 2004, 2011, 2018 g10 Code GmbH
 #
 # This file is free software; as a special exception the author gives
 # unlimited permission to copy and/or distribute it, with or without
 # modifications, as long as this notice is preserved.
 #
 # This file is distributed in the hope that it will be useful, but
 # WITHOUT ANY WARRANTY, to the extent permitted by law; without even the
 # implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
 AC_DEFUN([_AM_PATH_NPTH_CONFIG],
 [ AC_ARG_WITH(npth-prefix,
             AC_HELP_STRING([--with-npth-prefix=PFX],
                            [prefix where NPTH is installed (optional)]),
      npth_config_prefix="$withval", npth_config_prefix="")
   if test "x$npth_config_prefix" != x ; then
       NPTH_CONFIG="$npth_config_prefix/bin/npth-config"
   fi
 
   use_gpgrt_config=""
   if test x"$NPTH_CONFIG" != x -a x"$GPGRT_CONFIG" != x -a "$GPGRT_CONFIG" != "no"; then
     if CC=$CC $GPGRT_CONFIG npth >/dev/null 2>&1; then
       NPTH_CONFIG="$GPGRT_CONFIG npth"
       use_gpgrt_config=yes
     fi
   fi
   if test -z "$use_gpgrt_config"; then
     AC_PATH_PROG(NPTH_CONFIG, npth-config, no)
   fi
 
   if test "$NPTH_CONFIG" != "no" ; then
-    npth_version=`CC=$CC $NPTH_CONFIG --modversion`
+    if test -z "$use_gpgrt_config"; then
+      npth_version=`CC=$CC $NPTH_CONFIG --version`
+    else
+      npth_version=`CC=$CC $NPTH_CONFIG --modversion`
+    fi
   fi
   npth_version_major=`echo $npth_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\).*/\1/'`
   npth_version_minor=`echo $npth_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\).*/\2/'`
 ])
 
 dnl AM_PATH_NPTH([MINIMUM-VERSION,
 dnl               [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND ]]])
 dnl Test for libnpth and define NPTH_CFLAGS and NPTH_LIBS.
 dnl
 AC_DEFUN([AM_PATH_NPTH],
 [ AC_REQUIRE([_AM_PATH_NPTH_CONFIG])dnl
   tmp=ifelse([$1], ,1:0.91,$1)
   if echo "$tmp" | grep ':' >/dev/null 2>/dev/null ; then
      req_npth_api=`echo "$tmp"     | sed 's/\(.*\):\(.*\)/\1/'`
      min_npth_version=`echo "$tmp" | sed 's/\(.*\):\(.*\)/\2/'`
   else
      req_npth_api=1
      min_npth_version="$tmp"
   fi
 
   AC_MSG_CHECKING(for NPTH - version >= $min_npth_version)
   ok=no
   if test "$NPTH_CONFIG" != "no" ; then
     req_major=`echo $min_npth_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\)/\1/'`
     req_minor=`echo $min_npth_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\)/\2/'`
     if test "$npth_version_major" -gt "$req_major"; then
         ok=yes
     else
         if test "$npth_version_major" -eq "$req_major"; then
             if test "$npth_version_minor" -gt "$req_minor"; then
                ok=yes
             else
                if test "$npth_version_minor" -eq "$req_minor"; then
                   ok=yes
                fi
             fi
         fi
     fi
   fi
   if test $ok = yes; then
     AC_MSG_RESULT([yes ($npth_version)])
   else
     AC_MSG_RESULT(no)
   fi
   if test $ok = yes; then
-     # If we have a recent NPTH, we should also check that the
-     # API is compatible.
-     if test "$req_npth_api" -gt 0 ; then
+    # If we have a recent NPTH, we should also check that the
+    # API is compatible.
+    if test "$req_npth_api" -gt 0 ; then
+      if test -z "$use_gpgrt_config"; then
         tmp=`CC=$CC $NPTH_CONFIG --variable=api_version 2>/dev/null || echo 0`
-        if test "$tmp" -gt 0 ; then
-           AC_MSG_CHECKING([NPTH API version])
-           if test "$req_npth_api" -eq "$tmp" ; then
-             AC_MSG_RESULT([okay])
-           else
-             ok=no
-             AC_MSG_RESULT([does not match. want=$req_npth_api got=$tmp])
-           fi
+      else
+        tmp=`CC=$CC $NPTH_CONFIG --api-version 2>/dev/null || echo 0`
+      fi
+      if test "$tmp" -gt 0 ; then
+        AC_MSG_CHECKING([NPTH API version])
+        if test "$req_npth_api" -eq "$tmp" ; then
+          AC_MSG_RESULT([okay])
+        else
+          ok=no
+          AC_MSG_RESULT([does not match. want=$req_npth_api got=$tmp])
         fi
-     fi
+      fi
+    fi
   fi
   if test $ok = yes; then
     NPTH_CFLAGS=`CC=$CC $NPTH_CONFIG --cflags`
     NPTH_LIBS=`CC=$CC $NPTH_CONFIG --libs`
     ifelse([$2], , :, [$2])
-    npth_config_host=`CC=$CC $NPTH_CONFIG --variable=host 2>/dev/null || echo none`
+    if test -z "$use_gpgrt_config"; then
+      npth_config_host=`CC=$CC $NPTH_CONFIG --host 2>/dev/null || echo none`
+    else
+      npth_config_host=`CC=$CC $NPTH_CONFIG --variable=host 2>/dev/null || echo none`
+    fi
     if test x"$npth_config_host" != xnone ; then
       if test x"$npth_config_host" != x"$host" ; then
         AC_MSG_WARN([[
 ***
 *** The config script "$NPTH_CONFIG" was
 *** built for $npth_config_host and thus may not match the
 *** used host $host.
 *** You may want to use the configure option --with-npth-prefix
 *** to specify a matching config script.
 ***]])
       fi
     fi
   else
     NPTH_CFLAGS=""
     NPTH_LIBS=""
     ifelse([$3], , :, [$3])
   fi
   AC_SUBST(NPTH_CFLAGS)
   AC_SUBST(NPTH_LIBS)
 ])