diff --git a/include/aaruformat.h b/include/aaruformat.h
index b9acd1a..a3bd036 100644
--- a/include/aaruformat.h
+++ b/include/aaruformat.h
@@ -26,6 +26,7 @@
 #include "aaruformat/context.h"
 #include "aaruformat/crc64.h"
 #include "aaruformat/decls.h"
+#include "aaruformat/endian.h"
 #include "aaruformat/enums.h"
 #include "aaruformat/errors.h"
 #include "aaruformat/lru.h"
diff --git a/include/aaruformat/endian.h b/include/aaruformat/endian.h
new file mode 100644
index 0000000..4bbd735
--- /dev/null
+++ b/include/aaruformat/endian.h
@@ -0,0 +1,89 @@
+/*
+ * This file is part of the Aaru Data Preservation Suite.
+ * Copyright (c) 2019-2022 Natalia Portillo.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of the
+ * License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBAARUFORMAT_ENDIAN_H
+#define LIBAARUFORMAT_ENDIAN_H
+
+#ifdef _MSC_VER
+
+#include <stdlib.h>
+#define bswap_16(x) _byteswap_ushort(x)
+#define bswap_32(x) _byteswap_ulong(x)
+#define bswap_64(x) _byteswap_uint64(x)
+
+#elif defined(__APPLE__)
+
+// Mac OS X / Darwin features
+#include <libkern/OSByteOrder.h>
+
+#define bswap_16(x) OSSwapInt16(x)
+#define bswap_32(x) OSSwapInt32(x)
+#define bswap_64(x) OSSwapInt64(x)
+
+#elif defined(__sun) || defined(sun)
+
+#include <sys/byteorder.h>
+#define bswap_16(x) BSWAP_16(x)
+#define bswap_32(x) BSWAP_32(x)
+#define bswap_64(x) BSWAP_64(x)
+
+#elif defined(__FreeBSD__)
+
+#include <sys/endian.h>
+#define bswap_16(x) bswap16(x)
+#define bswap_32(x) bswap32(x)
+#define bswap_64(x) bswap64(x)
+
+#elif defined(__OpenBSD__)
+
+#include <sys/types.h>
+#define bswap_16(x) swap16(x)
+#define bswap_32(x) swap32(x)
+#define bswap_64(x) swap64(x)
+
+#elif defined(__NetBSD__)
+
+#include <sys/types.h>
+#include <machine/bswap.h>
+#if defined(__BSWAP_RENAME) && !defined(__bswap_32)
+#define bswap_16(x) bswap16(x)
+#define bswap_32(x) bswap32(x)
+#define bswap_64(x) bswap64(x)
+#endif
+
+#elif defined(__linux__)
+
+#include <byteswap.h>
+
+#else
+
+#include <stdint.h>
+
+#define bswap_16(x) ((uint16_t)((((uint16_t)(x)&0xff00) >> 8) | (((uint16_t)(x)&0x00ff) << 8)))
+#define bswap_32(x)                                                                                                    \
+    ((uint32_t)((((uint32_t)(x)&0xff000000) >> 24) | (((uint32_t)(x)&0x00ff0000) >> 8) |                               \
+                (((uint32_t)(x)&0x0000ff00) << 8) | (((uint32_t)(x)&0x000000ff) << 24)))
+#define bswap_64(x)                                                                                                    \
+    ((uint64_t)((((uint64_t)(x)&0xff00000000000000ULL) >> 56) | (((uint64_t)(x)&0x00ff000000000000ULL) >> 40) |        \
+                (((uint64_t)(x)&0x0000ff0000000000ULL) >> 24) | (((uint64_t)(x)&0x000000ff00000000ULL) >> 8) |         \
+                (((uint64_t)(x)&0x00000000ff000000ULL) << 8) | (((uint64_t)(x)&0x0000000000ff0000ULL) << 24) |         \
+                (((uint64_t)(x)&0x000000000000ff00ULL) << 40) | (((uint64_t)(x)&0x00000000000000ffULL) << 56)))
+
+#endif
+
+#endif //LIBAARUFORMAT_ENDIAN_H
diff --git a/src/open.c b/src/open.c
index 54ef813..4f20d5e 100644
--- a/src/open.c
+++ b/src/open.c
@@ -288,6 +288,10 @@ void* aaruf_open(const char* filepath)
                 }
 
                 crc64 = aaruf_crc64_data(data, blockHeader.length);
+
+                // Due to how C# wrote it, it is effectively reversed
+                if(ctx->header.imageMajorVersion <= AARUF_VERSION) crc64 = bswap_64(crc64);
+
                 if(crc64 != blockHeader.crc64)
                 {
                     fprintf(stderr,
@@ -763,6 +767,10 @@ void* aaruf_open(const char* filepath)
 
                 crc64 =
                     aaruf_crc64_data((const uint8_t*)ctx->trackEntries, ctx->tracksHeader.entries * sizeof(TrackEntry));
+
+                // Due to how C# wrote it, it is effectively reversed
+                if(ctx->header.imageMajorVersion <= AARUF_VERSION) crc64 = bswap_64(crc64);
+
                 if(crc64 != ctx->tracksHeader.crc64)
                 {
                     fprintf(stderr,
@@ -877,6 +885,10 @@ void* aaruf_open(const char* filepath)
                     if(readBytes == ctx->dumpHardwareHeader.length)
                     {
                         crc64 = aaruf_crc64_data(data, ctx->dumpHardwareHeader.length);
+
+                        // Due to how C# wrote it, it is effectively reversed
+                        if(ctx->header.imageMajorVersion <= AARUF_VERSION) crc64 = bswap_64(crc64);
+
                         if(crc64 != ctx->dumpHardwareHeader.crc64)
                         {
                             free(data);
@@ -1133,8 +1145,7 @@ void* aaruf_open(const char* filepath)
                 break;
             default:
                 fprintf(stderr,
-                        "libaaruformat: Unhandled block type %4.4s with data type %4.4s is indexed to be at %" PRIu64
-                        "\n",
+                        "libaaruformat: Unhandled block type %4.4s with data type %d is indexed to be at %" PRIu64 "\n",
                         (char*)&idxEntries[i].blockType,
                         (char*)&idxEntries[i].dataType,
                         idxEntries[i].offset);