diff --git a/src/file_wim.c b/src/file_wim.c
index 978d48a1..d5f66f4c 100644
--- a/src/file_wim.c
+++ b/src/file_wim.c
@@ -29,8 +29,11 @@
 #include <stdio.h>
 #include "types.h"
 #include "filegen.h"
+#include "common.h"
+#include "log.h"
 
 static void register_header_check_wim(file_stat_t *file_stat);
+/* http://go.microsoft.com/fwlink/?LinkId=92227 */
 
 const file_hint_t file_hint_wim= {
   .extension="wim",
@@ -42,10 +45,64 @@ const file_hint_t file_hint_wim= {
   .register_header_check=&register_header_check_wim
 };
 
+struct reshdr_disk_short
+{
+  union {
+    uint64_t flags;	/* one byte is a combination of RESHDR_FLAG_XXX */
+    uint64_t size;	/* the 7 low-bytes are used to store the size */
+  };
+  uint64_t offset;
+  uint64_t original_size;
+} __attribute__ ((__packed__));
+
+#define RESHDR_GET_SIZE(R) (le64(R.size) & 0x00FFFFFFFFFFFFFF)
+
+struct _WIMHEADER_V1_PACKED
+{
+  char			ImageTag[8];
+  uint32_t		cbSize;
+  uint32_t		dwVersion;
+  uint32_t		dwFlags;
+  uint32_t		dwCompressionSize;
+  unsigned char		gWIMGuid[16];
+  uint16_t		usPartNumber;
+  uint16_t		usTotalParts;
+  uint32_t		dwImageCount;
+  struct reshdr_disk_short	rhOffsetTable;
+  struct reshdr_disk_short	rhXmlData;
+  struct reshdr_disk_short	rhBootMetadata;
+  uint32_t		dwBootIndex;
+  struct reshdr_disk_short	rhIntegrity;
+  unsigned char		bUnused[60];
+} __attribute__ ((__packed__));
+
 static int header_check_wim(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
 {
+  const struct _WIMHEADER_V1_PACKED *hdr=(const struct _WIMHEADER_V1_PACKED *)buffer;
+  uint64_t size=le32(hdr->cbSize);
+  if(le32(hdr->cbSize) < sizeof(struct _WIMHEADER_V1_PACKED))
+    return 0;
+#ifdef DEBUG_WIM
+  log_info("cbSize %llu\n", (unsigned long long)le32(hdr->cbSize));
+  log_info("dwCompressionSize %llu\n", (unsigned long long)le32(hdr->dwCompressionSize));
+  log_info("rhOffsetTable %llu %llu\n", (unsigned long long)RESHDR_GET_SIZE(hdr->rhOffsetTable), (unsigned long long)le64(hdr->rhOffsetTable.offset));
+  log_info("rhXmlData %llu %llu\n", (unsigned long long)RESHDR_GET_SIZE(hdr->rhXmlData), (unsigned long long)le64(hdr->rhXmlData.offset));
+  log_info("rhBootMetadata %llu %llu\n", (unsigned long long)RESHDR_GET_SIZE(hdr->rhBootMetadata), (unsigned long long)le64(hdr->rhBootMetadata.offset));
+  log_info("rhIntegrity %llu %llu\n", (unsigned long long)RESHDR_GET_SIZE(hdr->rhIntegrity), (unsigned long long)le64(hdr->rhIntegrity.offset));
+#endif
+  if(RESHDR_GET_SIZE(hdr->rhOffsetTable) > 0 && RESHDR_GET_SIZE(hdr->rhOffsetTable) + le64(hdr->rhOffsetTable.offset) > size)
+    size=RESHDR_GET_SIZE(hdr->rhOffsetTable) + le64(hdr->rhOffsetTable.offset);
+  if(RESHDR_GET_SIZE(hdr->rhXmlData) > 0 && RESHDR_GET_SIZE(hdr->rhXmlData) + le64(hdr->rhXmlData.offset) > size)
+    size=RESHDR_GET_SIZE(hdr->rhXmlData) + le64(hdr->rhXmlData.offset);
+  if(RESHDR_GET_SIZE(hdr->rhBootMetadata) > 0 && RESHDR_GET_SIZE(hdr->rhBootMetadata) + le64(hdr->rhBootMetadata.offset) > size)
+    size=RESHDR_GET_SIZE(hdr->rhBootMetadata) + le64(hdr->rhBootMetadata.offset);
+  if(RESHDR_GET_SIZE(hdr->rhIntegrity) > 0 && RESHDR_GET_SIZE(hdr->rhIntegrity) + le64(hdr->rhIntegrity.offset) > size)
+    size=RESHDR_GET_SIZE(hdr->rhIntegrity) + le64(hdr->rhIntegrity.offset);
   reset_file_recovery(file_recovery_new);
   file_recovery_new->extension=file_hint_wim.extension;
+  file_recovery_new->calculated_file_size=size;
+  file_recovery_new->data_check=&data_check_size;
+  file_recovery_new->file_check=&file_check_size;
   return 1;
 }