diff --git a/sys/conf/files b/sys/conf/files
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -677,15 +677,17 @@
 	compile-with "${NORMAL_C} -I$S/contrib/ngatm"
 # xz
 dev/xz/xz_mod.c	optional xz \
-	compile-with "${NORMAL_C} -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
+	compile-with "${NORMAL_C} -DXZ_USE_CRC64 -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
 contrib/xz-embedded/linux/lib/xz/xz_crc32.c	optional xz \
-	compile-with "${NORMAL_C} -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
+	compile-with "${NORMAL_C} -DXZ_USE_CRC64 -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
+contrib/xz-embedded/linux/lib/xz/xz_crc64.c	optional xz \
+	compile-with "${NORMAL_C} -DXZ_USE_CRC64 -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
 contrib/xz-embedded/linux/lib/xz/xz_dec_bcj.c	optional xz \
-	compile-with "${NORMAL_C} -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
+	compile-with "${NORMAL_C} -DXZ_USE_CRC64 -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
 contrib/xz-embedded/linux/lib/xz/xz_dec_lzma2.c	optional xz \
-	compile-with "${NORMAL_C} -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
+	compile-with "${NORMAL_C} -DXZ_USE_CRC64 -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
 contrib/xz-embedded/linux/lib/xz/xz_dec_stream.c optional xz \
-	compile-with "${NORMAL_C} -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
+	compile-with "${NORMAL_C} -DXZ_USE_CRC64 -I$S/contrib/xz-embedded/freebsd/ -I$S/contrib/xz-embedded/linux/lib/xz/ -I$S/contrib/xz-embedded/linux/include/linux/"
 # Zstd
 contrib/zstd/lib/freebsd/zstd_kmalloc.c		optional zstdio compile-with ${ZSTD_C}
 contrib/zstd/lib/common/zstd_common.c		optional zstdio compile-with ${ZSTD_C}
diff --git a/sys/modules/xz/Makefile b/sys/modules/xz/Makefile
--- a/sys/modules/xz/Makefile
+++ b/sys/modules/xz/Makefile
@@ -7,12 +7,14 @@
 KMOD=	xz
 SRCS= \
 	xz_crc32.c \
+	xz_crc64.c \
 	xz_dec_bcj.c \
 	xz_dec_lzma2.c \
 	xz_dec_stream.c \
 	xz_mod.c
 
 CFLAGS+= \
+	-DXZ_USE_CRC64 \
 	-I${SRCTOP}/sys/contrib/xz-embedded/freebsd \
 	-I${SRCTOP}/sys/contrib/xz-embedded/linux/lib/xz \
 	-I${SRCTOP}/sys/contrib/xz-embedded/linux/include/linux