Index: lib/libsysdecode/Makefile
===================================================================
--- lib/libsysdecode/Makefile
+++ lib/libsysdecode/Makefile
@@ -124,8 +124,10 @@
 
 DEPENDOBJS+=	tables.h
 incdir=${SYSROOT:U${DESTDIR}}${INCLUDEDIR}
-tables.h: mktables ${incdir}/netinet/in.h ${incdir}/netinet/tcp.h \
-    ${incdir}/netinet6/in6.h
+.if !defined(_SKIP_BUILD)
+tblhdrs!=sh ${.CURDIR}/mktables -d ${incdir} | sort -u
+.endif
+tables.h: mktables ${tblhdrs:S?^?${incdir}/?}
 	sh ${.CURDIR}/mktables ${incdir} ${.TARGET}.tmp && \
 	    mv -f ${.TARGET}.tmp ${.TARGET}
 
Index: lib/libsysdecode/mktables
===================================================================
--- lib/libsysdecode/mktables
+++ lib/libsysdecode/mktables
@@ -37,9 +37,13 @@
 
 if [ -z "$1" ]
 then
-	echo "usage: sh $0 include-dir [output-file]"
+	echo "usage: sh $0 [-d] include-dir [output-file]"
 	exit 1
 fi
+if [ $1 = "-d" ]; then
+	emit_deps=1
+	shift
+fi
 include_dir=$1
 if [ -n "$2" ]; then
 	output_file="$2"
@@ -60,6 +64,11 @@
 	file=$3
 	excl=$4
 
+	if [ -n "$emit_deps" ]; then
+		echo $file
+		return
+	fi
+
 	if [ -z "$excl" ]; then
 		filter="cat"
 	else
@@ -84,10 +93,12 @@
 _EOF_
 }
 
-cat <<_EOF_
+if [ -z "$emit_deps" ]; then
+	cat <<_EOF_
 /* This file is auto-generated. */
 
 _EOF_
+fi
 
 gen_table "accessmode"      "[A-Z]_OK[[:space:]]+0?x?[0-9A-Fa-f]+"         "sys/unistd.h"
 gen_table "acltype"         "ACL_TYPE_[A-Z4_]+[[:space:]]+0x[0-9]+"        "sys/acl.h"