diff --git a/src/file_dir.c b/src/file_dir.c
index d1900932..1abbf0f3 100644
--- a/src/file_dir.c
+++ b/src/file_dir.c
@@ -35,10 +35,9 @@
 #include "filegen.h"
 #include "common.h"
 #include "fat_common.h"
-#include "fat_dir.h"
 
+/*@ requires \valid(file_stat); */
 static void register_header_check_dir(file_stat_t *file_stat);
-static int header_check_dir(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 file_hint_t file_hint_dir= {
   .extension="fat",
@@ -51,7 +50,7 @@ const file_hint_t file_hint_dir= {
 
 /*@
   @ requires \valid(file_recovery);
-  @ requires valid_read_string((char*)&file_recovery->filename);
+  @ requires valid_file_recovery(file_recovery);
   @ requires file_recovery->file_rename==&file_rename_fatdir;
   @*/
 static void file_rename_fatdir(file_recovery_t *file_recovery)
@@ -78,6 +77,7 @@ static void file_rename_fatdir(file_recovery_t *file_recovery)
   @ requires \valid_read((char *)buffer+(0..buffer_size-1));
   @ requires \valid(file_recovery);
   @ requires file_recovery->data_check == &data_check_fatdir;
+  @ requires file_recovery->calculated_file_size <= PHOTOREC_MAX_FILE_SIZE;
   @ ensures \result == DC_STOP;
   @ assigns file_recovery->calculated_file_size;
   @*/
@@ -91,11 +91,12 @@ static data_check_t data_check_fatdir(const unsigned char *buffer, const unsigne
 /*@
   @ requires buffer_size >= sizeof(struct msdos_dir_entry);
   @ requires \valid_read(buffer+(0..buffer_size-1));
-  @ requires \valid_read(file_recovery);
-  @ requires file_recovery->file_stat==\null || valid_read_string((char*)file_recovery->filename);
+  @ requires valid_file_recovery(file_recovery);
   @ requires \valid(file_recovery_new);
   @ requires file_recovery_new->blocksize > 0;
   @ requires separation: \separated(&file_hint_dir, buffer+(..), file_recovery, file_recovery_new);
+  @ assigns  *file_recovery_new;
+  @ ensures  \result!=0 ==> valid_file_recovery(file_recovery_new);
   @*/
 static int header_check_dir(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)
 {
@@ -111,9 +112,6 @@ static int header_check_dir(const unsigned char *buffer, const unsigned int buff
   return 1;
 }
 
-/*@
-  @ requires \valid(file_stat);
-  @*/
 static void register_header_check_dir(file_stat_t *file_stat)
 {
   register_header_check(0, ".          ", 8+3, &header_check_dir, file_stat);