--- configure.ac.orig	2022-09-28 17:04:28 UTC
+++ configure.ac
@@ -103,7 +103,10 @@ for lib in "" "-lresolv"; do
 	saved_LIBS="$LIBS"
 	LIBS="$LIBS $lib"
 	AC_LINK_IFELSE([
-		AC_LANG_PROGRAM([#include <resolv.h>],
+		AC_LANG_PROGRAM([[#include <sys/types.h>]
+		                 [#include <netinet/in.h>]
+		                 [#include <arpa/nameser.h>]
+		                 [#include <resolv.h>]],
 		                [res_query (0, 0, 0, 0, 0);
 		                 ns_get32 (NULL);
 		                 ns_get16 (NULL);])
@@ -285,13 +288,6 @@ else
 	AC_MSG_ERROR([cat is not available])
 else
 	AC_DEFINE_UNQUOTED(BIN_CAT, "$BIN_CAT", [path to cat, used in unit test])
-fi
-
-AC_PATH_PROG(BIN_TAC, tac, no)
-if test "$BIN_TAC" = "no" ; then
-	AC_MSG_ERROR([tac is not available])
-else
-	AC_DEFINE_UNQUOTED(BIN_TAC, "$BIN_TAC", [path to tac, used in unit test])
 fi
 
 AC_PATH_PROG(BIN_REV, rev, no)