Index: Makefile.inc1
===================================================================
--- Makefile.inc1
+++ Makefile.inc1
@@ -2032,8 +2032,7 @@
 		${_cddl_lib_libctf} \
 		lib/libutil lib/libpjdlog ${_lib_libypclnt} lib/libz lib/msun \
 		${_secure_lib_libcrypto} ${_lib_libldns} \
-		${_secure_lib_libssh} ${_secure_lib_libssl} \
-		gnu/lib/libdialog
+		${_secure_lib_libssh} ${_secure_lib_libssl}
 
 .if ${MK_GNUCXX} != "no"
 _prebuild_libs+= gnu/lib/libstdc++ gnu/lib/libsupc++
@@ -2041,6 +2040,11 @@
 gnu/lib/libsupc++__L: gnu/lib/libstdc++__L
 .endif
 
+.if ${MK_DIALOG} != "no"
+_prebuild_libs+= gnu/lib/libdialog
+gnu/lib/libdialog__L: lib/msun__L lib/ncurses/ncursesw__L
+.endif
+
 .if ${MK_LIBCPLUSPLUS} != "no"
 _prebuild_libs+= lib/libc++
 .endif
@@ -2190,8 +2194,6 @@
 .endif
 .endif
 
-gnu/lib/libdialog__L: lib/msun__L lib/ncurses/ncursesw__L
-
 .for _lib in ${_prereq_libs}
 ${_lib}__PL: .PHONY .MAKE
 .if exists(${.CURDIR}/${_lib})
Index: gnu/usr.bin/Makefile
===================================================================
--- gnu/usr.bin/Makefile
+++ gnu/usr.bin/Makefile
@@ -4,7 +4,6 @@
 
 SUBDIR= ${_binutils} \
 	${_cc} \
-	dialog \
 	diff \
 	diff3 \
 	${_dtc} \
@@ -49,6 +48,8 @@
 _cc=		cc
 .endif
 
+SUBDIR.${MK_DIALOG}+=	dialog
+
 SUBDIR_PARALLEL=
 
 .include <bsd.subdir.mk>
Index: lib/Makefile
===================================================================
--- lib/Makefile
+++ lib/Makefile
@@ -46,7 +46,6 @@
 	${_libdevdctl} \
 	libdevinfo \
 	libdevstat \
-	libdpv \
 	libdwarf \
 	libedit \
 	${_libelftc} \
@@ -197,6 +196,8 @@
 _libpe=		libpe
 .endif
 
+SUBDIR.${MK_DIALOG}+=	libdpv
+
 .if ${MK_FILE} != "no"
 _libmagic=	libmagic
 .endif
Index: share/mk/src.opts.mk
===================================================================
--- share/mk/src.opts.mk
+++ share/mk/src.opts.mk
@@ -76,6 +76,7 @@
     CTM \
     CUSE \
     CXX \
+    DIALOG \
     DICT \
     DMAGENT \
     DYNAMICROOT \
Index: tools/build/mk/OptionalObsoleteFiles.inc
===================================================================
--- tools/build/mk/OptionalObsoleteFiles.inc
+++ tools/build/mk/OptionalObsoleteFiles.inc
@@ -1334,6 +1334,21 @@
 OLD_FILES+=usr/libexec/cc1plus
 .endif
 
+.if ${MK_DIALOG} == no
+OLD_FILES+=usr/bin/dialog
+OLD_FILES+=usr/bin/dpv
+OLD_FILES+=usr/lib/libdialog.a
+OLD_FILES+=usr/lib/libdialog.so
+OLD_FILES+=usr/lib/libdialog.so.8
+OLD_FILES+=usr/lib/libdialog_p.a
+OLD_FILES+=usr/lib/libdpv.a
+OLD_FILES+=usr/lib/libdpv.so
+OLD_FILES+=usr/lib/libdpv.so.1
+OLD_FILES+=usr/lib/libdpv_p.a
+OLD_FILES+=usr/share/man/man1/dialog.1.gz
+OLD_FILES+=usr/share/man/man1/dpv.1.gz
+.endif
+
 .if ${MK_FMTREE} == no
 OLD_FILES+=usr/sbin/fmtree
 OLD_FILES+=usr/share/man/man8/fmtree.8.gz
Index: tools/build/options/WITHOUT_DIALOG
===================================================================
--- /dev/null
+++ tools/build/options/WITHOUT_DIALOG
@@ -0,0 +1,2 @@
+.\" $FreeBSD$
+Set to not build dialog(1), libdialog, and dpv(1).
Index: usr.bin/Makefile
===================================================================
--- usr.bin/Makefile
+++ usr.bin/Makefile
@@ -36,7 +36,6 @@
 	ctlstat \
 	cut \
 	dirname \
-	dpv \
 	du \
 	elf2aout \
 	elfdump \
@@ -199,6 +198,7 @@
 SUBDIR.${MK_BSD_CPIO}+=	cpio
 SUBDIR.${MK_CALENDAR}+=	calendar
 SUBDIR.${MK_CLANG}+=	clang
+SUBDIR.${MK_DIALOG}+=	dpv
 SUBDIR.${MK_EE}+=	ee
 SUBDIR.${MK_FILE}+=	file
 SUBDIR.${MK_FINGER}+=	finger