case "${host_cpu}-${host_os}" in
*-aix* | *-freebsd* | *-darwin*) x_rflag="-D_THREAD_SAFE";;
*solaris* | *-osf* | *-hpux*) x_rflag="-D_REENTRANT";;
+ *-linux*)
+ if test x"$PTHREAD_CFLAGS" = "x-pthread"; then
+ # For Linux/gcc "-pthread" implies "-lpthread". We need, however, to make this explicit
+ # in PTHREAD_LIBS such that a shared library to be built properly depends on libpthread.
+ PTHREAD_LIBS="-lpthread $PTHREAD_LIBS"
+ fi;;
esac
AC_MSG_RESULT(${x_rflag})
if test "x$x_rflag" != xno; then