diff --git a/src/file_x3f.c b/src/file_x3f.c
index 07068e29..0e21e040 100644
--- a/src/file_x3f.c
+++ b/src/file_x3f.c
@@ -36,7 +36,7 @@
 extern const file_hint_t file_hint_x3i;
 #endif
 
-/*@ requires \valid(file_stat); */
+/*@ requires valid_register_header_check(file_stat); */
 static void register_header_check_x3f(file_stat_t *file_stat);
 
 const file_hint_t file_hint_x3f = {
@@ -62,12 +62,9 @@ struct x3f_header
 
 /*@
   @ requires buffer_size >= sizeof(struct x3f_header);
-  @ 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_x3f, buffer+(..), file_recovery, file_recovery_new);
-  @ ensures  \result!=0 ==> valid_file_recovery(file_recovery_new);
+  @ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
+  @ ensures  valid_header_check_result(\result, file_recovery_new);
   @ assigns  *file_recovery_new;
   @*/
 static int header_check_x3f(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)