Index: uspace/lib/bithenge/src/failure.h
===================================================================
--- uspace/lib/bithenge/src/failure.h	(revision 8d2dd7f2d52fbc7693f94b66e451eeff3756d061)
+++ uspace/lib/bithenge/src/failure.h	(revision e211ea04fccf33d4cb2092f630a29e893e096a02)
@@ -44,13 +44,13 @@
 #include <stddef.h>
 
-int bithenge_should_fail(void);
+errno_t bithenge_should_fail(void);
 void *bithenge_failure_malloc(size_t);
 void *bithenge_failure_realloc(void *, size_t);
 ssize_t bithenge_failure_read(int, void *, size_t);
 off_t bithenge_failure_lseek(int, off_t, int);
-int bithenge_failure_ferror(FILE *);
+errno_t bithenge_failure_ferror(FILE *);
 char *bithenge_failure_str_ndup(const char *, size_t);
-int bithenge_failure_open(const char *, int);
-int bithenge_failure_fstat(int, struct stat *);
+errno_t bithenge_failure_open(const char *, int);
+errno_t bithenge_failure_fstat(int, struct stat *);
 
 #ifndef BITHENGE_FAILURE_DECLS_ONLY