diff --git a/lib/libz/Makefile b/lib/libz/Makefile
index abc490980deb..734da7fa539d 100644
--- a/lib/libz/Makefile
+++ b/lib/libz/Makefile
@@ -1,87 +1,87 @@
 #
 # $FreeBSD$
 #
 
 PACKAGE=	runtime
 LIB=		z
 SHLIBDIR?=	/lib
 SHLIB_MAJOR=	6
 MAN=		zlib.3 zopen.3
 MLINKS+=	zopen.3 zdopen.3
 
 ZLIBSRC=	${SRCTOP}/sys/contrib/zlib
 
 .PATH:		${ZLIBSRC}
 
 #CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
 #CFLAGS=-g -DDEBUG
 #CFLAGS=-O3 -Wall -Wwrite-strings -Wpointer-arith -Wconversion \
 #           -Wstrict-prototypes -Wmissing-prototypes
 
 CFLAGS+=	-D_LARGEFILE64_SOURCE=1 -DHAVE_HIDDEN -I${.CURDIR}
 
 WARNS?=		3
 
 CLEANFILES+=	example.o example foo.gz minigzip.o minigzip
 
 SRCS+=		adler32.c
 SRCS+=		compress.c
 SRCS+=		crc32.c
 SRCS+=		deflate.c
 SRCS+=		gzclose.c
 SRCS+=		gzlib.c
 SRCS+=		gzread.c
 SRCS+=		gzwrite.c
 SRCS+=		infback.c
 SRCS+=		inffast.c
 SRCS+=		inflate.c
 SRCS+=		inftrees.c
 SRCS+=		trees.c
 SRCS+=		uncompr.c
 SRCS+=		zutil.c
 
 # Wrapper relies on FreeBSD-specific fpos_t representation and non-portable
 # funopen. Not needed for bootstrapping, so just disable it.
 .if ${.MAKE.OS} == "FreeBSD" || !defined(BOOTSTRAPPING)
 SRCS+=		zopen.c
 .endif
 
 .if ${MACHINE_ARCH} == "i386" || ${MACHINE_ARCH} == "amd64"
 CFLAGS+=	-DUNALIGNED_OK
 .endif
 
 VERSION_DEF=	${.CURDIR}/Versions.def
 SYMBOL_MAPS=	${.CURDIR}/Symbol.map
 CFLAGS+=	-DSYMBOL_VERSIONING
 
 INCS=		zconf.h zlib.h
 
 .PATH:		${ZLIBSRC}/test
 
 ZLIB_VERSION!=	sed -n '/define.*ZLIB_VERSION/{s,[^0-9.],,gp;q;}' ${ZLIBSRC}/zlib.h
 
 zlib.pc: zlib.pc.in
 	sed -e 's,@prefix@,/usr,g ; \
 		s,@exec_prefix@,$${prefix},g ; \
 		s,@libdir@,${LIBDIR},g ; \
 		s,@sharedlibdir@,${SHLIBDIR},g ; \
 		s,@includedir@,${INCLUDEDIR},g ; \
 		s,@VERSION@,${ZLIB_VERSION},g ;' \
 		${.ALLSRC} > ${.TARGET}
 
 minigzip:	all minigzip.o
 	$(CC) -o minigzip minigzip.o -L. -lz
 
 example:	all example.o
 	$(CC) -o example example.o -L. -lz
 
 test: example minigzip
 	(export LD_LIBRARY_PATH=. ; ./example )
 	(export LD_LIBRARY_PATH=. ; \
 		echo hello world | ./minigzip | ./minigzip -d )
 
 PCFILES=	zlib.pc
 
 .include <bsd.lib.mk>
 
-CWARNFLAGS+=	${NO_WDEPRECATED_NON_PROTOTYPE}
+CWARNFLAGS+=	${NO_WDEPRECATED_NON_PROTOTYPE} ${NO_WSTRICT_PROTOTYPES}