dnl Check for systemd-daemon
 PKG_CHECK_MODULES(SYSTEMD, [libsystemd], [AC_DEFINE([HAVE_SYSTEMD],,[systemd is supported])],
                   [PKG_CHECK_MODULES(SYSTEMD, [libsystemd-daemon], [AC_DEFINE([HAVE_SYSTEMD],,[systemd-daemon is supported])], [AC_MSG_RESULT([systemd is not supported])])])
 CLAMD_LIBS="$CLAMD_LIBS $SYSTEMD_LIBS"
 CFLAGS="$CFLAGS $SYSTEMD_CFLAGS"
 
 dnl Check for systemd system unit installation directory (see man 7 daemon)
 AC_ARG_WITH([systemdsystemunitdir], AS_HELP_STRING([--with-systemdsystemunitdir=DIR], [Directory for systemd service files]),, [with_systemdsystemunitdir=auto])
 AS_IF([test "x$with_systemdsystemunitdir" = "xyes" -o "x$with_systemdsystemunitdir" = "xauto"], [
      def_systemdsystemunitdir=$($PKG_CONFIG --variable=systemdsystemunitdir systemd)
      AS_IF([test "x$def_systemdsystemunitdir" = "x"],
          [AS_IF([test "x$with_systemdsystemunitdir" = "xyes"], [AC_MSG_ERROR([systemd support requested but pkg-config unable to query systemd package])])
           with_systemdsystemunitdir=no],
          [with_systemdsystemunitdir=$def_systemdsystemunitdir])])
 AS_IF([test "x$with_systemdsystemunitdir" != "xno"],
       [AC_SUBST([systemdsystemunitdir], [$with_systemdsystemunitdir])])
 AM_CONDITIONAL(INSTALL_SYSTEMD_UNITS, [test "x$with_systemdsystemunitdir" != "xno"])
 AC_MSG_RESULT([checking for systemd system unit installation directory... $with_systemdsystemunitdir])