diff --git a/0001-squashfs-tools-Add-zstd-support.patch b/0001-squashfs-tools-Add-zstd-support.patch
new file mode 100644
index 0000000..d0ba23c
--- /dev/null
+++ b/0001-squashfs-tools-Add-zstd-support.patch
@@ -0,0 +1,413 @@
+From 6113361316d5ce5bfdc118d188e5617a1fcd747c Mon Sep 17 00:00:00 2001
+From: Sean Purcell <me@seanp.xyz>
+Date: Mon, 14 Aug 2017 22:46:04 -0700
+Subject: [PATCH 1/4] squashfs-tools: Add zstd support
+
+This patch adds zstd support to squashfs-tools. It works with zstd
+versions >= 1.0.0. It was originally written by Sean Purcell.
+
+Signed-off-by: Sean Purcell <me@seanp.xyz>
+Signed-off-by: Nick Terrell <terrelln@fb.com>
+---
+ squashfs-tools/Makefile       |  20 +++
+ squashfs-tools/compressor.c   |   8 ++
+ squashfs-tools/squashfs_fs.h  |   1 +
+ squashfs-tools/zstd_wrapper.c | 254 ++++++++++++++++++++++++++++++++++
+ squashfs-tools/zstd_wrapper.h |  48 +++++++
+ 5 files changed, 331 insertions(+)
+ create mode 100644 squashfs-tools/zstd_wrapper.c
+ create mode 100644 squashfs-tools/zstd_wrapper.h
+
+diff --git a/squashfs-tools/Makefile b/squashfs-tools/Makefile
+index 52d2582..22fc559 100644
+--- a/squashfs-tools/Makefile
++++ b/squashfs-tools/Makefile
+@@ -75,6 +75,18 @@ GZIP_SUPPORT = 1
+ #LZMA_SUPPORT = 1
+ #LZMA_DIR = ../../../../LZMA/lzma465
+ 
++
++########### Building ZSTD support ############
++#
++# The ZSTD library is supported
++# ZSTD homepage: http://zstd.net
++# ZSTD source repository: https://github.com/facebook/zstd
++#
++# To build using the ZSTD library - install the library and uncomment the
++# ZSTD_SUPPORT line below.
++#
++#ZSTD_SUPPORT = 1
++
+ ######## Specifying default compression ########
+ #
+ # The next line specifies which compression algorithm is used by default
+@@ -177,6 +189,14 @@ LIBS += -llz4
+ COMPRESSORS += lz4
+ endif
+ 
++ifeq ($(ZSTD_SUPPORT),1)
++CFLAGS += -DZSTD_SUPPORT
++MKSQUASHFS_OBJS += zstd_wrapper.o
++UNSQUASHFS_OBJS += zstd_wrapper.o
++LIBS += -lzstd
++COMPRESSORS += zstd
++endif
++
+ ifeq ($(XATTR_SUPPORT),1)
+ ifeq ($(XATTR_DEFAULT),1)
+ CFLAGS += -DXATTR_SUPPORT -DXATTR_DEFAULT
+diff --git a/squashfs-tools/compressor.c b/squashfs-tools/compressor.c
+index 525e316..02b5e90 100644
+--- a/squashfs-tools/compressor.c
++++ b/squashfs-tools/compressor.c
+@@ -65,6 +65,13 @@ static struct compressor xz_comp_ops = {
+ extern struct compressor xz_comp_ops;
+ #endif
+ 
++#ifndef ZSTD_SUPPORT
++static struct compressor zstd_comp_ops = {
++	ZSTD_COMPRESSION, "zstd"
++};
++#else
++extern struct compressor zstd_comp_ops;
++#endif
+ 
+ static struct compressor unknown_comp_ops = {
+ 	0, "unknown"
+@@ -77,6 +84,7 @@ struct compressor *compressor[] = {
+ 	&lzo_comp_ops,
+ 	&lz4_comp_ops,
+ 	&xz_comp_ops,
++	&zstd_comp_ops,
+ 	&unknown_comp_ops
+ };
+ 
+diff --git a/squashfs-tools/squashfs_fs.h b/squashfs-tools/squashfs_fs.h
+index 791fe12..afca918 100644
+--- a/squashfs-tools/squashfs_fs.h
++++ b/squashfs-tools/squashfs_fs.h
+@@ -277,6 +277,7 @@ typedef long long		squashfs_inode;
+ #define LZO_COMPRESSION		3
+ #define XZ_COMPRESSION		4
+ #define LZ4_COMPRESSION		5
++#define ZSTD_COMPRESSION	6
+ 
+ struct squashfs_super_block {
+ 	unsigned int		s_magic;
+diff --git a/squashfs-tools/zstd_wrapper.c b/squashfs-tools/zstd_wrapper.c
+new file mode 100644
+index 0000000..dcab75a
+--- /dev/null
++++ b/squashfs-tools/zstd_wrapper.c
+@@ -0,0 +1,254 @@
++/*
++ * Copyright (c) 2017
++ * Phillip Lougher <phillip@squashfs.org.uk>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version 2,
++ * or (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * zstd_wrapper.c
++ *
++ * Support for ZSTD compression http://zstd.net
++ */
++
++#include <stdio.h>
++#include <string.h>
++#include <stdlib.h>
++#include <zstd.h>
++#include <zstd_errors.h>
++
++#include "squashfs_fs.h"
++#include "zstd_wrapper.h"
++#include "compressor.h"
++
++static int compression_level = ZSTD_DEFAULT_COMPRESSION_LEVEL;
++
++/*
++ * This function is called by the options parsing code in mksquashfs.c
++ * to parse any -X compressor option.
++ *
++ * This function returns:
++ *	>=0 (number of additional args parsed) on success
++ *	-1 if the option was unrecognised, or
++ *	-2 if the option was recognised, but otherwise bad in
++ *	   some way (e.g. invalid parameter)
++ *
++ * Note: this function sets internal compressor state, but does not
++ * pass back the results of the parsing other than success/failure.
++ * The zstd_dump_options() function is called later to get the options in
++ * a format suitable for writing to the filesystem.
++ */
++static int zstd_options(char *argv[], int argc)
++{
++	if (strcmp(argv[0], "-Xcompression-level") == 0) {
++		if (argc < 2) {
++			fprintf(stderr, "zstd: -Xcompression-level missing "
++				"compression level\n");
++			fprintf(stderr, "zstd: -Xcompression-level it should "
++				"be 1 <= n <= %d\n", ZSTD_maxCLevel());
++			goto failed;
++		}
++
++		compression_level = atoi(argv[1]);
++		if (compression_level < 1 ||
++		    compression_level > ZSTD_maxCLevel()) {
++			fprintf(stderr, "zstd: -Xcompression-level invalid, it "
++				"should be 1 <= n <= %d\n", ZSTD_maxCLevel());
++			goto failed;
++		}
++
++		return 1;
++	}
++
++	return -1;
++failed:
++	return -2;
++}
++
++/*
++ * This function is called by mksquashfs to dump the parsed
++ * compressor options in a format suitable for writing to the
++ * compressor options field in the filesystem (stored immediately
++ * after the superblock).
++ *
++ * This function returns a pointer to the compression options structure
++ * to be stored (and the size), or NULL if there are no compression
++ * options.
++ */
++static void *zstd_dump_options(int block_size, int *size)
++{
++	static struct zstd_comp_opts comp_opts;
++
++	/* don't return anything if the options are all default */
++	if (compression_level == ZSTD_DEFAULT_COMPRESSION_LEVEL)
++		return NULL;
++
++	comp_opts.compression_level = compression_level;
++
++	SQUASHFS_INSWAP_COMP_OPTS(&comp_opts);
++
++	*size = sizeof(comp_opts);
++	return &comp_opts;
++}
++
++/*
++ * This function is a helper specifically for the append mode of
++ * mksquashfs.  Its purpose is to set the internal compressor state
++ * to the stored compressor options in the passed compressor options
++ * structure.
++ *
++ * In effect this function sets up the compressor options
++ * to the same state they were when the filesystem was originally
++ * generated, this is to ensure on appending, the compressor uses
++ * the same compression options that were used to generate the
++ * original filesystem.
++ *
++ * Note, even if there are no compressor options, this function is still
++ * called with an empty compressor structure (size == 0), to explicitly
++ * set the default options, this is to ensure any user supplied
++ * -X options on the appending mksquashfs command line are over-ridden.
++ *
++ * This function returns 0 on sucessful extraction of options, and -1 on error.
++ */
++static int zstd_extract_options(int block_size, void *buffer, int size)
++{
++	struct zstd_comp_opts *comp_opts = buffer;
++
++	if (size == 0) {
++		/* Set default values */
++		compression_level = ZSTD_DEFAULT_COMPRESSION_LEVEL;
++		return 0;
++	}
++
++	/* we expect a comp_opts structure of sufficient size to be present */
++	if (size < sizeof(*comp_opts))
++		goto failed;
++
++	SQUASHFS_INSWAP_COMP_OPTS(comp_opts);
++
++	if (comp_opts->compression_level < 1 ||
++	    comp_opts->compression_level > ZSTD_maxCLevel()) {
++		fprintf(stderr, "zstd: bad compression level in compression "
++			"options structure\n");
++		goto failed;
++	}
++
++	compression_level = comp_opts->compression_level;
++
++	return 0;
++
++failed:
++	fprintf(stderr, "zstd: error reading stored compressor options from "
++		"filesystem!\n");
++
++	return -1;
++}
++
++static void zstd_display_options(void *buffer, int size)
++{
++	struct zstd_comp_opts *comp_opts = buffer;
++
++	/* we expect a comp_opts structure of sufficient size to be present */
++	if (size < sizeof(*comp_opts))
++		goto failed;
++
++	SQUASHFS_INSWAP_COMP_OPTS(comp_opts);
++
++	if (comp_opts->compression_level < 1 ||
++	    comp_opts->compression_level > ZSTD_maxCLevel()) {
++		fprintf(stderr, "zstd: bad compression level in compression "
++			"options structure\n");
++		goto failed;
++	}
++
++	printf("\tcompression-level %d\n", comp_opts->compression_level);
++
++	return;
++
++failed:
++	fprintf(stderr, "zstd: error reading stored compressor options from "
++		"filesystem!\n");
++}
++
++/*
++ * This function is called by mksquashfs to initialise the
++ * compressor, before compress() is called.
++ *
++ * This function returns 0 on success, and -1 on error.
++ */
++static int zstd_init(void **strm, int block_size, int datablock)
++{
++	ZSTD_CCtx *cctx = ZSTD_createCCtx();
++
++	if (!cctx) {
++		fprintf(stderr, "zstd: failed to allocate compression "
++			"context!\n");
++		return -1;
++	}
++
++	*strm = cctx;
++	return 0;
++}
++
++static int zstd_compress(void *strm, void *dest, void *src, int size,
++			 int block_size, int *error)
++{
++	const size_t res = ZSTD_compressCCtx((ZSTD_CCtx*)strm, dest, block_size,
++					     src, size, compression_level);
++
++	if (ZSTD_isError(res)) {
++		/* FIXME:
++		 * zstd does not expose stable error codes. The error enum may
++		 * change between versions. Until upstream zstd stablizes the
++		 * error codes, we have no way of knowing why the error occurs.
++		 * zstd shouldn't fail to compress any input unless there isn't
++		 * enough output space. We assume that is the cause and return
++		 * the special error code for not enough output space.
++		 */
++		return 0;
++	}
++
++	return (int)res;
++}
++
++static int zstd_uncompress(void *dest, void *src, int size, int outsize,
++			   int *error)
++{
++	const size_t res = ZSTD_decompress(dest, outsize, src, size);
++
++	if (ZSTD_isError(res)) {
++		fprintf(stderr, "\t%d %d\n", outsize, size);
++
++		*error = (int)ZSTD_getErrorCode(res);
++		return -1;
++	}
++
++	return (int)res;
++}
++
++static void zstd_usage(void)
++{
++	fprintf(stderr, "\t  -Xcompression-level <compression-level>\n");
++	fprintf(stderr, "\t\t<compression-level> should be 1 .. %d (default "
++		"%d)\n", ZSTD_maxCLevel(), ZSTD_DEFAULT_COMPRESSION_LEVEL);
++}
++
++struct compressor zstd_comp_ops = {
++	.init = zstd_init,
++	.compress = zstd_compress,
++	.uncompress = zstd_uncompress,
++	.options = zstd_options,
++	.dump_options = zstd_dump_options,
++	.extract_options = zstd_extract_options,
++	.display_options = zstd_display_options,
++	.usage = zstd_usage,
++	.id = ZSTD_COMPRESSION,
++	.name = "zstd",
++	.supported = 1
++};
+diff --git a/squashfs-tools/zstd_wrapper.h b/squashfs-tools/zstd_wrapper.h
+new file mode 100644
+index 0000000..4fbef0a
+--- /dev/null
++++ b/squashfs-tools/zstd_wrapper.h
+@@ -0,0 +1,48 @@
++#ifndef ZSTD_WRAPPER_H
++#define ZSTD_WRAPPER_H
++/*
++ * Squashfs
++ *
++ * Copyright (c) 2017
++ * Phillip Lougher <phillip@squashfs.org.uk>
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version 2,
++ * or (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * zstd_wrapper.h
++ *
++ */
++
++#ifndef linux
++#define __BYTE_ORDER BYTE_ORDER
++#define __BIG_ENDIAN BIG_ENDIAN
++#define __LITTLE_ENDIAN LITTLE_ENDIAN
++#else
++#include <endian.h>
++#endif
++
++#if __BYTE_ORDER == __BIG_ENDIAN
++extern unsigned int inswap_le16(unsigned short);
++extern unsigned int inswap_le32(unsigned int);
++
++#define SQUASHFS_INSWAP_COMP_OPTS(s) { \
++	(s)->compression_level = inswap_le32((s)->compression_level); \
++}
++#else
++#define SQUASHFS_INSWAP_COMP_OPTS(s)
++#endif
++
++/* Default compression */
++#define ZSTD_DEFAULT_COMPRESSION_LEVEL 15
++
++struct zstd_comp_opts {
++	int compression_level;
++};
++#endif
+-- 
+2.19.1
+
diff --git a/squashfs-tools.spec b/squashfs-tools.spec
index d80aeb7..8b851e6 100644
--- a/squashfs-tools.spec
+++ b/squashfs-tools.spec
@@ -26,12 +26,16 @@ Patch3:  cve-2015-4645.patch
 Patch4:  local-cve-fix.patch
 # sys/sysmacros.h is no longer included by sys/types.h
 Patch5:  glibc.patch
+# zstd compression support from https://github.com/plougher/squashfs-tools
+Patch6:  0001-squashfs-tools-Add-zstd-support.patch
+
 BuildRequires:  gcc
 BuildRequires: zlib-devel
 BuildRequires: xz-devel
 BuildRequires: lzo-devel
 BuildRequires: libattr-devel
 BuildRequires: lz4-devel
+BuildRequires: libzstd-devel
 
 %description
 Squashfs is a highly compressed read-only filesystem for Linux.  This package
@@ -45,11 +49,12 @@ contains the utilities for manipulating squashfs filesystems.
 %patch3 -p1
 %patch4 -p0
 %patch5 -p0
+%patch6 -p1
 
 %build
 %set_build_flags
 pushd squashfs-tools
-CFLAGS="%{optflags}" XZ_SUPPORT=1 LZO_SUPPORT=1 LZMA_XZ_SUPPORT=1 LZ4_SUPPORT=1 make %{?_smp_mflags}
+CFLAGS="%{optflags}" XZ_SUPPORT=1 LZO_SUPPORT=1 LZMA_XZ_SUPPORT=1 LZ4_SUPPORT=1 ZSTD_SUPPORT=1 make %{?_smp_mflags}
 
 %install
 mkdir -p %{buildroot}%{_sbindir} %{buildroot}%{_mandir}/man1
@@ -68,6 +73,9 @@ install -m 644 %{SOURCE2} %{buildroot}%{_mandir}/man1/unsquashfs.1
 %{_sbindir}/unsquashfs
 
 %changelog
+* Mon Jun 24 2019 Bruno Wolff III <bruno@wolff.to> - 4.3-21
+- Add zstd compression support (Sean Purcell via github.com/plougher/squashfs-tools)
+
 * Tue May 21 2019 Bruno Wolff III <bruno@wolff.to> - 4.3-20
 - Fix issue with LDFLAGS not being set