--- a/configure.in
+++ b/configure.in
@@ -23,6 +23,9 @@
 AC_PROG_CC
 AC_PROG_YACC
 AC_PROG_LEX
+
+PKG_PROG_PKG_CONFIG
+
 AC_REQUIRE_CPP
 AC_AIX
 ACX_PTHREAD(, AC_MSG_ERROR(cannot find pthread; see the INSTALL notes))
@@ -51,7 +54,7 @@
 	)
 )
 if test "$ac_cv_type_in_addr_t" != yes; then
-	AC_DEFINE_UNQUOTED(in_addr_t, $ac_cv_type_in_addr_t)
+	AC_DEFINE_UNQUOTED([in_addr_t], [$ac_cv_type_in_addr_t], [addr_t])
 fi
 
 AC_CACHE_CHECK(for socklen_t, ac_cv_type_socklen_t,
@@ -65,7 +68,7 @@
 	)
 )
 if test "$ac_cv_type_socklen_t" != yes; then
-	AC_DEFINE_UNQUOTED(socklen_t, $ac_cv_type_socklen_t)
+	AC_DEFINE_UNQUOTED([socklen_t], [$ac_cv_type_socklen_t], [socklen_t])
 fi
 
 AC_CACHE_CHECK(for struct sockaddr_storage, ac_cv_sockaddr_storage,
@@ -79,7 +82,7 @@
 	)
 )
 if test "$ac_cv_sockaddr_storage" != no; then
-	AC_DEFINE(HAVE_SOCKADDR_STORAGE)
+	AC_DEFINE(HAVE_SOCKADDR_STORAGE, 1, [have sockaddr_storage])
 fi
 
 AC_CACHE_CHECK(for struct ether_addr, ac_cv_ether_addr,
@@ -94,7 +97,7 @@
 	)
 )
 if test "$ac_cv_ether_addr" != no; then
-	AC_DEFINE(HAVE_ETHER_ADDR)
+	AC_DEFINE(HAVE_ETHER_ADDR, 1, [have ether_addr])
 fi
 
 dnl Check for network system libraries.
@@ -144,20 +147,21 @@
 case "$ac_cv_have_curses" in
 
 slang)
-	AC_DEFINE(HAVE_SLCURSES)
-	AC_DEFINE(HAVE_HAS_COLORS)
+	AC_DEFINE(HAVE_SLCURSES, 1, [have slcurses])
+	AC_DEFINE(HAVE_HAS_COLORS, 1, [have colors])
 	;;
 ncurses)
-	AC_DEFINE(HAVE_NCURSES)
+	PKG_CHECK_MODULES(ncurses,ncurses, [LIBS="$LIBS $ncurses_LIBS"], [ncurses not found])
+	AC_DEFINE(HAVE_NCURSES, 1, [have ncurses])
 	AC_CHECK_FUNCS(has_colors)
 	;;
 n_curses)
 	CFLAGS="-I/usr/include/ncurses $CFLAGS"
-	AC_DEFINE(HAVE_NCURSES)
+	AC_DEFINE(HAVE_NCURSES, 1, [have n_curses])
 	AC_CHECK_FUNCS(has_colors)
 	;;
 curses)
-	AC_DEFINE(HAVE_CURSES)
+	AC_DEFINE(HAVE_CURSES, 1, [have curses])
 	AC_CHECK_FUNCS(has_colors)
 	;;
 *)