diff --git a/src/file_ifo.c b/src/file_ifo.c
index 1577ec40..bd8838d1 100644
--- a/src/file_ifo.c
+++ b/src/file_ifo.c
@@ -32,6 +32,7 @@
 #include "filegen.h"
 #include "common.h"
 
+/*@ requires \valid(file_stat); */
 static void register_header_check_ifo(file_stat_t *file_stat);
 
 const file_hint_t file_hint_ifo= {
@@ -50,6 +51,17 @@ struct ifo_hdr
   uint32_t ls_IFO;
 } __attribute__ ((gcc_struct, __packed__));
 
+/*@
+  @ requires buffer_size >= sizeof(struct ifo_hdr);
+  @ requires \valid_read(buffer+(0..buffer_size-1));
+  @ requires valid_file_recovery(file_recovery);
+  @ requires \valid(file_recovery_new);
+  @ requires file_recovery_new->blocksize > 0;
+  @ requires separation: \separated(&file_hint_ifo, buffer+(..), file_recovery, file_recovery_new);
+  @ ensures \result == 0 || \result == 1;
+  @ ensures  \result!=0 ==> valid_file_recovery(file_recovery_new);
+  @ assigns  *file_recovery_new;
+  @*/
 static int header_check_ifo(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 ifo_hdr *hdr=(const struct ifo_hdr *)buffer;
@@ -66,6 +78,8 @@ static void register_header_check_ifo(file_stat_t *file_stat)
   static const unsigned char ifo_header_vmg[12]=  { 'D', 'V', 'D', 'V', 'I', 'D', 'E', 'O', '-', 'V', 'M', 'G'};
   static const unsigned char ifo_header_vts[12]=  { 'D', 'V', 'D', 'V', 'I', 'D', 'E', 'O', '-', 'V', 'T', 'S'};
   register_header_check(0, ifo_header_vmg, sizeof(ifo_header_vmg), &header_check_ifo, file_stat);
+#ifndef __FRAMAC__
   register_header_check(0, ifo_header_vts, sizeof(ifo_header_vts), &header_check_ifo, file_stat);
+#endif
 }
 #endif