33 files changed, 50 insertions, 50 deletions

diff --git a/cad/astk-serveur/Makefile b/cad/astk-serveur/Makefile
index 5f7a8f80ace8..1081eb6bbc89 100644
--- a/cad/astk-serveur/Makefile
+++ b/cad/astk-serveur/Makefile
@@ -62,7 +62,7 @@ WRKCONF=	${WRKDIR}/${PORTNAME}-${PORTVERSION:R}/configuration
 .if !defined(CLIENT_SEUL)
 WRKSRC=		${WRKDIR}/${PORTNAME}-${PORTVERSION:R}/ASTK_SERV
 PATCHDIR=	${MASTERDIR}/files
-PLIST_SUB=	ASTKDIR=${LINSTDIR}/ASTK_SERV SERV="" CLIENT="@comment "\
+PLIST_SUB+=	ASTKDIR=${LINSTDIR}/ASTK_SERV SERV="" CLIENT="@comment "\
 		vaster=${vaster}
 PATCH2RM=	bin/as_run bin/parallel_cp etc/asrun etc/profile.sh	\
 		asrun/config.py asrun/installation.py asrun/system.py	\
@@ -90,7 +90,7 @@ TKPNG_VER=	0.9
 TKPNG=		tkpng${TKPNG_VER}
 WRKSRC=		${WRKDIR}/${PORTNAME}-${PORTVERSION:R}/ASTK_CLIENT
 PATCHDIR=	${MASTERDIR}/files.client
-PLIST_SUB=	ASTKDIR=${LINSTDIR}/ASTK_CLIENT SERV="@comment " CLIENT="" vaster=""	\
+PLIST_SUB+=	ASTKDIR=${LINSTDIR}/ASTK_CLIENT SERV="@comment " CLIENT="" vaster=""	\
 		BWidget_DIR=${LINSTDIR}/ASTK_CLIENT/lib/BWidget-${BWidget_VER}
 PATCH2RM=	bin/astk bin/bsf etc/astkrc/outils lib/init.tcl lib/tkselecteur.tcl
 .endif
diff --git a/databases/dbh/Makefile b/databases/dbh/Makefile
index d84b7abb74e2..9e8be08ad7dd 100644
--- a/databases/dbh/Makefile
+++ b/databases/dbh/Makefile
@@ -28,10 +28,10 @@ GTKDOC_DESC=	Enable GTK html documentation
 
 .if ${PORT_OPTIONS:MGTKDOC}
 CONFIGURE_ARGS+=	--enable-gtk-doc-html
-PLIST_SUB=	GTKDOC=""
+PLIST_SUB+=	GTKDOC=""
 .else
 CONFIGURE_ARGS+=	--disable-gtk-doc-html
-PLIST_SUB=	GTKDOC="@comment "
+PLIST_SUB+=	GTKDOC="@comment "
 .endif
 
 post-patch:
diff --git a/databases/libgda5/Makefile b/databases/libgda5/Makefile
index 99ae80381e4d..f8634daddc40 100644
--- a/databases/libgda5/Makefile
+++ b/databases/libgda5/Makefile
@@ -37,7 +37,7 @@ CONFIGURE_ARGS=	--without-oracle \
 .include <bsd.port.options.mk>
 
 VERSION=	5.0
-PLIST_SUB=	VERSION=${VERSION}
+PLIST_SUB+=	VERSION=${VERSION}
 
 .if ${LIBGDA5_SLAVE}!="no"
 USE_GNOME+=	libgda5
diff --git a/databases/pglogical/Makefile b/databases/pglogical/Makefile
index f7fef5b17873..3b1229bdfbeb 100644
--- a/databases/pglogical/Makefile
+++ b/databases/pglogical/Makefile
@@ -29,9 +29,9 @@ DOCS_PORTDOCS=	*
 .include <bsd.port.pre.mk>
 
 .if ${PGSQL_VER:M9.4}
-PLIST_SUB=	PGSQL94=""
+PLIST_SUB+=	PGSQL94=""
 .else
-PLIST_SUB=	PGSQL94="@comment "
+PLIST_SUB+=	PGSQL94="@comment "
 .endif
 
 # FFI
diff --git a/devel/grumpy/Makefile b/devel/grumpy/Makefile
index 9c560a3fa4ba..798e07de84f1 100644
--- a/devel/grumpy/Makefile
+++ b/devel/grumpy/Makefile
@@ -21,10 +21,10 @@ BINARY_ALIAS=	python=${PYTHON_CMD}
 .include <bsd.port.options.mk>
 
 .if ${ARCH} == "amd64"
-PLIST_SUB=	ARCH=amd64
+PLIST_SUB+=	ARCH=amd64
 .endif
 .if ${ARCH} == "i386"
-PLIST_SUB=	ARCH=386
+PLIST_SUB+=	ARCH=386
 .endif
 
 do-install:
diff --git a/devel/pth/Makefile b/devel/pth/Makefile
index 76bbfe1ebbb7..2c7099871807 100644
--- a/devel/pth/Makefile
+++ b/devel/pth/Makefile
@@ -30,10 +30,10 @@ CONFLICTS?=	pth-hard-2.*
 
 .if ${PKGNAMESUFFIX} == "-hard"
 CONFIGURE_ARGS+=	--enable-syscall-hard --disable-syscall-soft
-PLIST_SUB=	PTHREAD="@comment "
+PLIST_SUB+=	PTHREAD="@comment "
 .else
 CONFIGURE_ARGS+=	--enable-syscall-soft --enable-pthread
-PLIST_SUB=	PTHREAD=""
+PLIST_SUB+=	PTHREAD=""
 .endif
 
 post-patch:
diff --git a/devel/smack/Makefile b/devel/smack/Makefile
index aa72c2fb7741..6e14293f6c47 100644
--- a/devel/smack/Makefile
+++ b/devel/smack/Makefile
@@ -28,11 +28,11 @@ OPTIONS_DEFINE=	EXAMPLES
 .include <bsd.port.options.mk>
 
 .if ${PORT_OPTIONS:MEXAMPLES}
-PLIST_SUB=	EXAMPLES=""
+PLIST_SUB+=	EXAMPLES=""
 CMAKE_ARGS=	-DENABLE_EXAMPLES=ON
 .else
 CMAKE_ARGS=	-DENABLE_EXAMPLES=OFF
-PLIST_SUB=	EXAMPLES="@comment "
+PLIST_SUB+=	EXAMPLES="@comment "
 .endif
 
 .include <bsd.port.mk>
diff --git a/devel/statcvs/Makefile b/devel/statcvs/Makefile
index 7a3e74ae9704..00a4445ec6b8 100644
--- a/devel/statcvs/Makefile
+++ b/devel/statcvs/Makefile
@@ -39,9 +39,9 @@ DOCS_ALL_TARGET=javadoc
 .include <bsd.port.pre.mk>
 
 .if ${JAVA_PORT_VERSION} == "1.6.0"
-PLIST_SUB=	JDK6=""
+PLIST_SUB+=	JDK6=""
 .else
-PLIST_SUB=	JDK6="@comment "
+PLIST_SUB+=	JDK6="@comment "
 .endif
 
 do-install:
diff --git a/emulators/mame/Makefile b/emulators/mame/Makefile
index 84a97a673120..1bcf8c1d021d 100644
--- a/emulators/mame/Makefile
+++ b/emulators/mame/Makefile
@@ -62,7 +62,7 @@ EMULATOR=	${MSUBTARGET}64
 .else
 EMULATOR=	${MSUBTARGET}
 .endif
-PLIST_SUB=	EMULATOR=${EMULATOR}
+PLIST_SUB+=	EMULATOR=${EMULATOR}
 
 post-patch:
 	@${RM} ${WRKSRC}/3rdparty/bx/include/compat/freebsd/dirent.h
diff --git a/emulators/mtools/Makefile b/emulators/mtools/Makefile
index f4d4c2673136..a9bd61c457ce 100644
--- a/emulators/mtools/Makefile
+++ b/emulators/mtools/Makefile
@@ -38,10 +38,10 @@ CONFIGURE_ENV+=	ac_cv_header_iconv_h=no
 
 .if ${PORT_OPTIONS:MX11}
 USE_XORG=	x11 sm ice xau
-PLIST_SUB=	X11=""
+PLIST_SUB+=	X11=""
 .else
 CONFIGURE_ARGS+=	--without-x
-PLIST_SUB=	X11="@comment "
+PLIST_SUB+=	X11="@comment "
 MAKE_ENV+=	WITHOUT_X11=yes
 .endif
 
diff --git a/german/BBBike/Makefile b/german/BBBike/Makefile
index 28cd5687db81..efe8872259d6 100644
--- a/german/BBBike/Makefile
+++ b/german/BBBike/Makefile
@@ -59,7 +59,7 @@ MYDESTDIR=	${STAGEDIR}${PREFIX}/BBBike
 .if exists(${PERL5})
 LOCAL_PERL_ARCH!=	${PERL5} -MConfig -e '$$x = qq{$$Config{version}/$$Config{archname}}; $$x =~ s{/}{\\\\/}g; print $$x'
 .endif
-PLIST_SUB=		LOCAL_PERL_ARCH=${LOCAL_PERL_ARCH}
+PLIST_SUB+=		LOCAL_PERL_ARCH=${LOCAL_PERL_ARCH}
 BBBIKE_PERL_EXE=	bbbike cbbbike bbbikeclient cmdbbbike smsbbbike
 
 post-patch:
diff --git a/graphics/OpenEXR/Makefile b/graphics/OpenEXR/Makefile
index 37973038380c..ccef56995a4e 100644
--- a/graphics/OpenEXR/Makefile
+++ b/graphics/OpenEXR/Makefile
@@ -57,7 +57,7 @@ USE_GCC=	yes
 MAJORVER=	2_2
 VER=		23
 
-PLIST_SUB=	MAJORVER=${MAJORVER}
+PLIST_SUB+=	MAJORVER=${MAJORVER}
 PLIST_SUB+=	VER=${VER}
 
 post-patch:
diff --git a/graphics/tgif/Makefile b/graphics/tgif/Makefile
index 402b7866ad3c..451d8624588b 100644
--- a/graphics/tgif/Makefile
+++ b/graphics/tgif/Makefile
@@ -32,9 +32,9 @@ USE_XORG=	x11 xext xt sm ice
 .if ${PORT_OPTIONS:MNLS}
 USES+=		gettext
 IMAKEDEFINES+=	WITH_NLS
-PLIST_SUB=	NLS=""
+PLIST_SUB+=	NLS=""
 .else
-PLIST_SUB=	NLS="@comment "
+PLIST_SUB+=	NLS="@comment "
 .endif
 .if ${PORT_OPTIONS:MA4SIZE}
 IMAKEDEFINES+=	WITH_A4SIZE
diff --git a/japanese/skkinput3/Makefile b/japanese/skkinput3/Makefile
index 0adb02bd6854..1c978e8e4759 100644
--- a/japanese/skkinput3/Makefile
+++ b/japanese/skkinput3/Makefile
@@ -31,9 +31,9 @@ SKK10_DESC=	Install SKK10 elisp files
 .include <bsd.port.options.mk>
 
 .if ${PORT_OPTIONS:MSKK10}
-PLIST_SUB=	SKK8="@comment " SKK10=""
+PLIST_SUB+=	SKK8="@comment " SKK10=""
 .else
-PLIST_SUB=	SKK8="" SKK10="@comment "
+PLIST_SUB+=	SKK8="" SKK10="@comment "
 .endif
 
 .if ${PORT_OPTIONS:MDBSKKD}
diff --git a/lang/gcc48/Makefile b/lang/gcc48/Makefile
index 2b2ea70ba984..652ae366ea60 100644
--- a/lang/gcc48/Makefile
+++ b/lang/gcc48/Makefile
@@ -102,7 +102,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--enable-languages=${LANGUAGES}
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/gcc49/Makefile b/lang/gcc49/Makefile
index ba783bbcb4e9..a4db46650d39 100644
--- a/lang/gcc49/Makefile
+++ b/lang/gcc49/Makefile
@@ -102,7 +102,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--enable-languages=${LANGUAGES}
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/gcc5/Makefile b/lang/gcc5/Makefile
index 4763d13d72d6..5c49f45056df 100644
--- a/lang/gcc5/Makefile
+++ b/lang/gcc5/Makefile
@@ -101,7 +101,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--with-system-zlib
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/gcc6-devel/Makefile b/lang/gcc6-devel/Makefile
index 110617bac275..ba2fcdbcb366 100644
--- a/lang/gcc6-devel/Makefile
+++ b/lang/gcc6-devel/Makefile
@@ -117,7 +117,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--with-system-zlib
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/gcc6/Makefile b/lang/gcc6/Makefile
index ecdfdfce3019..866fe18702bb 100644
--- a/lang/gcc6/Makefile
+++ b/lang/gcc6/Makefile
@@ -117,7 +117,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--with-system-zlib
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/gcc7-devel/Makefile b/lang/gcc7-devel/Makefile
index 01f6b37ecb55..538804b0a862 100644
--- a/lang/gcc7-devel/Makefile
+++ b/lang/gcc7-devel/Makefile
@@ -101,7 +101,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--with-system-zlib
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/gcc7/Makefile b/lang/gcc7/Makefile
index 559df00a3dd3..54d83bf78a77 100644
--- a/lang/gcc7/Makefile
+++ b/lang/gcc7/Makefile
@@ -97,7 +97,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--with-system-zlib
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/gcc8-devel/Makefile b/lang/gcc8-devel/Makefile
index 1afc9dff5e8d..b21e2f275671 100644
--- a/lang/gcc8-devel/Makefile
+++ b/lang/gcc8-devel/Makefile
@@ -99,7 +99,7 @@ CONFIGURE_ARGS+=--disable-nls \
 		--with-system-zlib
 MAKE_ARGS+=	MAKEINFOFLAGS="--no-split"
 USE_LDCONFIG=	${TARGLIB}
-PLIST_SUB=	GCC_VERSION=${GCC_VERSION} \
+PLIST_SUB+=	GCC_VERSION=${GCC_VERSION} \
 		GNU_HOST=${CONFIGURE_TARGET} \
 		SUFFIX=${SUFFIX}
 INFO=		gcc${SUFFIX}/cpp \
diff --git a/lang/modula3/Makefile b/lang/modula3/Makefile
index 8cbdfbb26287..d8a99adc0006 100644
--- a/lang/modula3/Makefile
+++ b/lang/modula3/Makefile
@@ -77,7 +77,7 @@ MARCH=		x86_64
 
 NEWBOOTNAME=	m3-bootstrap.${MARCH}.${OPSYS:tu}.${OSREL:S/.//}.tar.bz2
 M3TARGET=	${MARCH}_${OPSYS:tu}
-PLIST_SUB=	T=${M3TARGET} P=cm3/pkg B=cm3/bin L=cm3/lib
+PLIST_SUB+=	T=${M3TARGET} P=cm3/pkg B=cm3/bin L=cm3/lib
 .endif
 
 post-extract:
diff --git a/lang/smlnj/Makefile b/lang/smlnj/Makefile
index 7a9c5ae687c9..a879bb06ada5 100644
--- a/lang/smlnj/Makefile
+++ b/lang/smlnj/Makefile
@@ -57,7 +57,7 @@ DISTFILES+=	MLRISC.tgz ckit.tgz cml.tgz doc.tgz heap2asm.tgz \
 		ml-burg.tgz ml-lpt.tgz ml-lex.tgz ml-yacc.tgz nlffi.tgz \
 		smlnj-lib.tgz trace-debug-profile.tgz
 
-PLIST_SUB=	MLARCH=${MLARCH}
+PLIST_SUB+=	MLARCH=${MLARCH}
 
 .if ${PORT_OPTIONS:MPOSITION64} || defined(ML_POSITION64)
 ML_POSITION64?=	${PORT_OPTIONS:MPOSITION64}
diff --git a/mail/cclient/Makefile b/mail/cclient/Makefile
index a34d08227792..556c296714d2 100644
--- a/mail/cclient/Makefile
+++ b/mail/cclient/Makefile
@@ -55,7 +55,7 @@ SHLIBBASE=	c-client4
 SHLIBMAJ=	9
 SHLIBNAME=	lib${SHLIBBASE}.so.${SHLIBMAJ}
 MAKE_ENV+=	SHLIBNAME=${SHLIBNAME} SHLIBBASE=${SHLIBBASE}
-PLIST_SUB=	SHLIBNAME=${SHLIBNAME} SHLIBBASE=${SHLIBBASE}
+PLIST_SUB+=	SHLIBNAME=${SHLIBNAME} SHLIBBASE=${SHLIBBASE}
 
 post-patch:
 .for file in Makefile src/osdep/unix/Makefile src/osdep/unix/Makefile.gss
diff --git a/mail/panda-cclient/Makefile b/mail/panda-cclient/Makefile
index 1e5b14d7aeb1..a612b766ea8c 100644
--- a/mail/panda-cclient/Makefile
+++ b/mail/panda-cclient/Makefile
@@ -57,7 +57,7 @@ SHLIBBASE=	c-client4
 SHLIBMAJ=	10
 SHLIBNAME=	lib${SHLIBBASE}.so.${SHLIBMAJ}
 MAKE_ENV+=	SHLIBNAME=${SHLIBNAME} SHLIBBASE=${SHLIBBASE}
-PLIST_SUB=	SHLIBNAME=${SHLIBNAME} SHLIBBASE=${SHLIBBASE}
+PLIST_SUB+=	SHLIBNAME=${SHLIBNAME} SHLIBBASE=${SHLIBBASE}
 
 pre-configure:
 .for file in Makefile src/osdep/unix/Makefile src/osdep/unix/Makefile.gss
diff --git a/news/leafnode/Makefile b/news/leafnode/Makefile
index 3bc785cace23..206a87819b27 100644
--- a/news/leafnode/Makefile
+++ b/news/leafnode/Makefile
@@ -31,7 +31,7 @@ LEAFNODE_SPOOLDIR?=/var/spool/news
 LEAFNODE_SPOOLDIR?=${LOCALBASE}/var/spool/leafnode
 .endif
 LEAFNODE_SPOOLDIR?=/var/spool/leafnode
-PLIST_SUB=	SPOOLDIR=${LEAFNODE_SPOOLDIR} REALPREFIX=${PREFIX}
+PLIST_SUB+=	SPOOLDIR=${LEAFNODE_SPOOLDIR} REALPREFIX=${PREFIX}
 
 CONFIGURE_ARGS=	--sysconfdir=${PREFIX}/etc/leafnode \
 		--with-spooldir=${LEAFNODE_SPOOLDIR} --with-ipv6 \
diff --git a/print/pdflib/Makefile b/print/pdflib/Makefile
index cef8d4a71b49..1efb64137991 100644
--- a/print/pdflib/Makefile
+++ b/print/pdflib/Makefile
@@ -29,11 +29,11 @@ PERL_USES=	perl5
 .include <bsd.port.pre.mk>
 
 .if ${PORT_OPTIONS:MPERL}
-PLIST_SUB=	PERL=""
+PLIST_SUB+=	PERL=""
 CONFIGURE_ARGS+=--with-perl=${PERL}
 .else
 CONFIGURE_ARGS+=--with-perl=no
-PLIST_SUB=	PERL="@comment "
+PLIST_SUB+=	PERL="@comment "
 .endif
 
 .if ${PORT_OPTIONS:MJAVA}
diff --git a/science/cgnslib/Makefile b/science/cgnslib/Makefile
index ff2382e74df4..0c1681cd058d 100644
--- a/science/cgnslib/Makefile
+++ b/science/cgnslib/Makefile
@@ -34,13 +34,13 @@ OPTIONS_DEFAULT=HDF5 TESTS TOOLS
 LIB_DEPENDS+=	libhdf5.so:science/hdf5
 CMAKE_ARGS+=	-DCGNS_ENABLE_HDF5:BOOL=TRUE -DHDF5_NEED_ZLIB:BOOL=TRUE	\
 		-DHDF5_INCLUDE_PATH:PATH="${LOCALBASE}/include"
-PLIST_SUB=	HDF5=""
+PLIST_SUB+=	HDF5=""
 . if ${PORT_OPTIONS:MSZIP}
 CMAKE_ARGS+=	-DHDF5_NEED_SZIP:BOOL=OFF
 . endif
 .else
 CMAKE_ARGS+=	-DCGNS_ENABLE_HDF5:BOOL=OFF
-PLIST_SUB=	HDF5="@comment "
+PLIST_SUB+=	HDF5="@comment "
 .endif
 
 .if ${PORT_OPTIONS:MTESTS}
@@ -56,9 +56,9 @@ USE_XORG=	x11 xmu
 CMAKE_ARGS+=	-DCGNS_BUILD_CGNSTOOLS:BOOL=TRUE			\
 		-DTCL_INCLUDE_PATH:STRING="${TCL_INCLUDEDIR}"	\
 		-DTK_INCLUDE_PATH:STRING="${TK_INCLUDEDIR}"
-PLIST_SUB=	TOOLS=""
+PLIST_SUB+=	TOOLS=""
 .else
-PLIST_SUB=	TOOLS="@comment "
+PLIST_SUB+=	TOOLS="@comment "
 .endif
 
 LIBVER=		${PORTVERSION:R}
diff --git a/sysutils/xcdroast/Makefile b/sysutils/xcdroast/Makefile
index c778fed06ce5..32228e8de498 100644
--- a/sysutils/xcdroast/Makefile
+++ b/sysutils/xcdroast/Makefile
@@ -34,9 +34,9 @@ CONFIGURE_ARGS=	--with-cdrtools-prefix=${LOCALBASE} \
 
 .if ${PORT_OPTIONS:MNLS}
 CONFIGURE_ARGS+=--disable-nls
-PLIST_SUB=	NLS="@comment "
+PLIST_SUB+=	NLS="@comment "
 .else
-PLIST_SUB=	NLS=""
+PLIST_SUB+=	NLS=""
 .endif
 
 .if ${PORT_OPTIONS:MGTK2}
diff --git a/www/polipo/Makefile b/www/polipo/Makefile
index 7bd0034a3b74..40e86a74fbc4 100644
--- a/www/polipo/Makefile
+++ b/www/polipo/Makefile
@@ -27,7 +27,7 @@ SUB_FILES=	pkg-message pkg-install pkg-deinstall 400.polipo
 SUB_LIST+=	USER=${PUSER} GROUP=${PGRP} DESTDIR=${DESTDIR} PCONFIGDIR=${PCONFIGDIR} \
 		PCACHEDIR=${PCACHEDIR} PPIDDIR=${PPIDDIR} PPIDFILE=${PPIDFILE} \
 		PLOGFILE=${PLOGFILE}
-PLIST_SUB=	PCACHEDIR=${PCACHEDIR}
+PLIST_SUB+=	PCACHEDIR=${PCACHEDIR}
 
 # polipo installation options, propagated to install scripts
 PUSER?=		polipo
diff --git a/x11/rxvt-unicode/Makefile b/x11/rxvt-unicode/Makefile
index 6ffa49634e54..12900eccbd64 100644
--- a/x11/rxvt-unicode/Makefile
+++ b/x11/rxvt-unicode/Makefile
@@ -73,10 +73,10 @@ PATCH_DEPENDS+=	p5-Encode-HanExtra>=0:chinese/p5-Encode-HanExtra \
 CONFIGURE_ARGS+=	--disable-perl
 USES+=			perl5
 USE_PERL5=		build
-PLIST_SUB=		PERL="@comment "
+PLIST_SUB+=		PERL="@comment "
 .else
 USES+=			perl5
-PLIST_SUB=		PERL=""
+PLIST_SUB+=		PERL=""
 .endif
 
 # disable XIM (X Input Method) protocol support
diff --git a/x11/xkbset/Makefile b/x11/xkbset/Makefile
index 4c220a5c1f2a..4cd33dcbcee7 100644
--- a/x11/xkbset/Makefile
+++ b/x11/xkbset/Makefile
@@ -28,10 +28,10 @@ GUI_DESC=	Install Tk GUI
 
 .if ${PORT_OPTIONS:MGUI}
 RUN_DEPENDS+=	p5-Tk>=0:x11-toolkits/p5-Tk
-PLIST_SUB=	GUI=""
+PLIST_SUB+=	GUI=""
 MAKE_ARGS+=	INSTALL_SCRIPT="${INSTALL_SCRIPT}"
 .else
-PLIST_SUB=	GUI="@comment "
+PLIST_SUB+=	GUI="@comment "
 MAKE_ARGS+=	INSTALL_SCRIPT=:
 .endif