diff --git a/doc/magic.header.txt b/doc/magic.header.txt
index 40c1949..0a2a5f1 100644
--- a/doc/magic.header.txt
+++ b/doc/magic.header.txt
@@ -8,7 +8,8 @@ Byte	Content
 5	LRZIP Minor Version Number
 6-14	Source File Size
 16-20	LZMA Properties Encoded (lc,lp,pb,fb, and dictionary size)
-21-22	not used
+21	Flag that md5sum hash is stored at the end of the archive
+22	not used
 23-48	Stream 1 header data
 49-74	Stream 2 header data
 
diff --git a/main.c b/main.c
index 23ffb29..766007c 100644
--- a/main.c
+++ b/main.c
@@ -78,6 +78,12 @@ static void write_magic(int fd_in, int fd_out)
 			magic[i + 16] = (char)control.lzma_properties[i];
 	}
 
+	/* This is a flag that the archive contains an md5 sum at the end
+	 * which can be used as an integrity check instead of crc check.
+	 * crc is still stored for compatibility with 0.5 versions.
+	 */
+	magic[21] = 1;
+
 	if (unlikely(lseek(fd_out, 0, SEEK_SET)))
 		fatal("Failed to seek to BOF to write Magic Header\n");
 
@@ -89,7 +95,7 @@ static void read_magic(int fd_in, i64 *expected_size)
 {
 	char magic[24];
 	uint32_t v;
-	int i;
+	int md5, i;
 
 	if (unlikely(read(fd_in, magic, sizeof(magic)) != sizeof(magic)))
 		fatal("Failed to read magic header\n");
@@ -116,6 +122,12 @@ static void read_magic(int fd_in, i64 *expected_size)
 		for (i = 0; i < 5; i++)
 			control.lzma_properties[i] = magic[i + 16];
 	}
+
+	/* Whether this archive contains md5 data at the end or not */
+	md5 = magic[21];
+	if (md5 == 1)
+		control.flags |= FLAG_MD5;
+
 	print_verbose("Detected lrzip version %d.%d file.\n", control.major_version, control.minor_version);
 	if (control.major_version > LRZIP_MAJOR_VERSION ||
 	    (control.major_version == LRZIP_MAJOR_VERSION && control.minor_version > LRZIP_MINOR_VERSION))
@@ -300,6 +312,14 @@ static void decompress_file(void)
 		fatal("Failed to open history file %s\n", control.outfile);
 
 	read_magic(fd_in, &expected_size);
+	if (NO_MD5)
+		print_verbose("Not performing MD5 hash check\n");
+	if (HAS_MD5)
+		print_verbose("MD5 ");
+	else
+		print_verbose("CRC32 ");
+	print_verbose("being used for integrity testing.\n");
+
 	print_progress("Decompressing...");
 
 	runzip_fd(fd_in, fd_out, fd_hist, expected_size);
@@ -411,6 +431,21 @@ static void get_fileinfo(void)
 	print_output("Decompressed file size: %llu\n", expected_size);
 	print_output("Compressed file size: %llu\n", infile_size);
 	print_output("Compression ratio: %.3Lf\n", cratio);
+	if (HAS_MD5) {
+		char md5_stored[MD5_DIGEST_SIZE];
+		int i;
+
+		print_output("MD5 used for integrity testing\n");
+		if (unlikely(lseek(fd_in, -MD5_DIGEST_SIZE, SEEK_END)) == -1)
+			fatal("Failed to seek to md5 data in runzip_fd\n");
+		if (unlikely(read(fd_in, md5_stored, MD5_DIGEST_SIZE) != MD5_DIGEST_SIZE))
+			fatal("Failed to read md5 data in runzip_fd\n");
+		print_output("MD5: ");
+		for (i = 0; i < MD5_DIGEST_SIZE; i++)
+			print_output("%02x", md5_stored[i] & 0xFF);
+		print_output("\n");
+	} else
+		print_output("CRC32 used for integrity testing\n");
 
 	if (STDIN) {
 		if (unlikely(unlink(control.infile)))
diff --git a/runzip.c b/runzip.c
index cad0750..98568a0 100644
--- a/runzip.c
+++ b/runzip.c
@@ -82,8 +82,10 @@ static i64 unzip_literal(void *ss, i64 len, int fd_out, uint32 *cksum)
 	if (unlikely(write_1g(fd_out, buf, (size_t)stream_read) != (ssize_t)stream_read))
 		fatal("Failed to write literal buffer of size %lld\n", stream_read);
 
-	*cksum = CrcUpdate(*cksum, buf, stream_read);
-	md5_process_bytes(buf, stream_read, &control.ctx);
+	if (!HAS_MD5)
+		*cksum = CrcUpdate(*cksum, buf, stream_read);
+	if (!NO_MD5)
+		md5_process_bytes(buf, stream_read, &control.ctx);
 
 	free(buf);
 	return stream_read;
@@ -122,8 +124,10 @@ static i64 unzip_match(void *ss, i64 len, int fd_out, int fd_hist, uint32 *cksum
 		if (unlikely(write_1g(fd_out, off_buf, (size_t)n) != (ssize_t)n))
 			fatal("Failed to write %d bytes in unzip_match\n", n);
 
-		*cksum = CrcUpdate(*cksum, off_buf, n);
-		md5_process_bytes(off_buf, n, &control.ctx);
+		if (!HAS_MD5)
+			*cksum = CrcUpdate(*cksum, off_buf, n);
+		if (!NO_MD5)
+			md5_process_bytes(off_buf, n, &control.ctx);
 
 		len -= n;
 		off_buf += n;
@@ -211,9 +215,12 @@ static i64 runzip_chunk(int fd_in, int fd_out, int fd_hist, i64 expected_size, i
 		}
 	}
 
-	good_cksum = read_u32(ss, 0);
-	if (unlikely(good_cksum != cksum))
-		fatal("Bad checksum 0x%08x - expected 0x%08x\n", cksum, good_cksum);
+	if (!HAS_MD5) {
+		good_cksum = read_u32(ss, 0);
+		if (unlikely(good_cksum != cksum))
+			fatal("Bad checksum: 0x%08x - expected: 0x%08x\n", cksum, good_cksum);
+		print_maxverbose("Checksum for block: 0x%08x\n", cksum);
+	}
 
 	if (unlikely(close_stream_in(ss)))
 		fatal("Failed to close stream!\n");
@@ -227,11 +234,12 @@ static i64 runzip_chunk(int fd_in, int fd_out, int fd_hist, i64 expected_size, i
 i64 runzip_fd(int fd_in, int fd_out, int fd_hist, i64 expected_size)
 {
 	char md5_resblock[MD5_DIGEST_SIZE];
+	char md5_stored[MD5_DIGEST_SIZE];
 	struct timeval start,end;
 	i64 total = 0;
-	int j;
 
-	md5_init_ctx (&control.ctx);
+	if (!NO_MD5)
+		md5_init_ctx (&control.ctx);
 	gettimeofday(&start,NULL);
 
 	while (total < expected_size)
@@ -241,12 +249,33 @@ i64 runzip_fd(int fd_in, int fd_out, int fd_hist, i64 expected_size)
 	print_progress("\nAverage DeCompression Speed: %6.3fMB/s\n",
 			(total / 1024 / 1024) / (double)((end.tv_sec-start.tv_sec)? : 1));
 
-	md5_finish_ctx (&control.ctx, md5_resblock);
-	if (HASH_CHECK || VERBOSE) {
-		print_output("MD5: ");
-		for (j = 0; j < MD5_DIGEST_SIZE; j++)
-			print_output("%02x", md5_resblock[j] & 0xFF);
-		print_output("\n");
+	if (!NO_MD5) {
+		int i,j;
+
+		md5_finish_ctx (&control.ctx, md5_resblock);
+		if (HAS_MD5) {
+			if (unlikely(lseek(fd_in, -MD5_DIGEST_SIZE, SEEK_END)) == -1)
+				fatal("Failed to seek to md5 data in runzip_fd\n");
+			if (unlikely(read(fd_in, md5_stored, MD5_DIGEST_SIZE) != MD5_DIGEST_SIZE))
+				fatal("Failed to read md5 data in runzip_fd\n");
+			for (i = 0; i < MD5_DIGEST_SIZE; i++)
+				if (md5_stored[i] != md5_resblock[i]) {
+					print_output("MD5 CHECK FAILED.\nStored:");
+					for (j = 0; j < MD5_DIGEST_SIZE; j++)
+						print_output("%02x", md5_stored[j] & 0xFF);
+					print_output("\nOutput file:");
+					for (j = 0; j < MD5_DIGEST_SIZE; j++)
+						print_output("%02x", md5_resblock[j] & 0xFF);
+					fatal("\n");
+				}
+		}
+
+		if (HASH_CHECK || MAX_VERBOSE) {
+			print_output("MD5: ");
+			for (i = 0; i < MD5_DIGEST_SIZE; i++)
+				print_output("%02x", md5_resblock[i] & 0xFF);
+			print_output("\n");
+		}
 	}
 
 	return total;
diff --git a/rzip.c b/rzip.c
index ad5b7ea..3eacdb7 100644
--- a/rzip.c
+++ b/rzip.c
@@ -916,12 +916,14 @@ retry:
 	close_streamout_threads();
 
 	md5_finish_ctx (&control.ctx, md5_resblock);
-	if (HASH_CHECK || VERBOSE) {
+	if (HASH_CHECK || MAX_VERBOSE) {
 		print_output("MD5: ");
 		for (j = 0; j < MD5_DIGEST_SIZE; j++)
 			print_output("%02x", md5_resblock[j] & 0xFF);
 		print_output("\n");
 	}
+	if (unlikely(write(control.fd_out, md5_resblock, MD5_DIGEST_SIZE) != MD5_DIGEST_SIZE))
+		fatal("Failed to write md5 in rzip_fd\n");
 
 	gettimeofday(&current, NULL);
 	if (STDIN)
diff --git a/rzip.h b/rzip.h
index 11de485..f3096c3 100644
--- a/rzip.h
+++ b/rzip.h
@@ -213,6 +213,7 @@ static inline i64 get_ram(void)
 #define FLAG_MAXRAM		(1 << 15)
 #define FLAG_UNLIMITED		(1 << 16)
 #define FLAG_HASH		(1 << 17)
+#define FLAG_MD5		(1 << 18)
 
 #define FLAG_VERBOSE (FLAG_VERBOSITY | FLAG_VERBOSITY_MAX)
 #define FLAG_NOT_LZMA (FLAG_NO_COMPRESS | FLAG_LZO_COMPRESS | FLAG_BZIP2_COMPRESS | FLAG_ZLIB_COMPRESS | FLAG_ZPAQ_COMPRESS)
@@ -237,6 +238,9 @@ static inline i64 get_ram(void)
 #define MAXRAM		(control.flags & FLAG_MAXRAM)
 #define UNLIMITED	(control.flags & FLAG_UNLIMITED)
 #define HASH_CHECK	(control.flags & FLAG_HASH)
+#define HAS_MD5		(control.flags & FLAG_MD5)
+
+#define NO_MD5		(!(HASH_CHECK) && !(HAS_MD5))
 
 #define BITS32		(sizeof(long) == 4)