diff --git a/arch/sim/src/sim/posix/sim_hostfs.c b/arch/sim/src/sim/posix/sim_hostfs.c
index 65927897dc..e60042d03f 100644
--- a/arch/sim/src/sim/posix/sim_hostfs.c
+++ b/arch/sim/src/sim/posix/sim_hostfs.c
@@ -125,7 +125,7 @@ static void host_stat_convert(struct stat *hostbuf, struct nuttx_stat_s *buf)
  * Name: host_open
  ****************************************************************************/
 
-int host_open(const char *pathname, int flags, nuttx_mode_t mode)
+int host_open(const char *pathname, int flags, int mode)
 {
   int mapflags = 0;
 
@@ -545,7 +545,7 @@ int host_unlink(const char *pathname)
  * Name: host_mkdir
  ****************************************************************************/
 
-int host_mkdir(const char *pathname, nuttx_mode_t mode)
+int host_mkdir(const char *pathname, int mode)
 {
   /* Just call the host's mkdir routine */
 
diff --git a/include/nuttx/fs/hostfs.h b/include/nuttx/fs/hostfs.h
index af96c4fa9e..24f41c9e73 100644
--- a/include/nuttx/fs/hostfs.h
+++ b/include/nuttx/fs/hostfs.h
@@ -130,6 +130,7 @@ typedef int32_t      nuttx_off_t;
 typedef uint32_t     nuttx_blkcnt_t;
 #  endif
 typedef unsigned int nuttx_mode_t;
+typedef int          nuttx_fsid_t[2];
 
 /* These must match the definition in include/time.h */
 
@@ -157,14 +158,15 @@ struct nuttx_dirent_s
 
 struct nuttx_statfs_s
 {
-  uint32_t     f_type;     /* Type of filesystem */
-  nuttx_size_t f_namelen;  /* Maximum length of filenames */
-  nuttx_size_t f_bsize;    /* Optimal block size for transfers */
-  nuttx_off_t  f_blocks;   /* Total data blocks in the file system of this size */
-  nuttx_off_t  f_bfree;    /* Free blocks in the file system */
-  nuttx_off_t  f_bavail;   /* Free blocks avail to non-superuser */
-  nuttx_off_t  f_files;    /* Total file nodes in the file system */
-  nuttx_off_t  f_ffree;    /* Free file nodes in the file system */
+  uint32_t       f_type;     /* Type of filesystem */
+  nuttx_size_t   f_namelen;  /* Maximum length of filenames */
+  nuttx_size_t   f_bsize;    /* Optimal block size for transfers */
+  nuttx_blkcnt_t f_blocks;   /* Total data blocks in the file system of this size */
+  nuttx_blkcnt_t f_bfree;    /* Free blocks in the file system */
+  nuttx_blkcnt_t f_bavail;   /* Free blocks avail to non-superuser */
+  nuttx_blkcnt_t f_files;    /* Total file nodes in the file system */
+  nuttx_blkcnt_t f_ffree;    /* Free file nodes in the file system */
+  nuttx_fsid_t   f_fsid;     /* Encode device type, not yet in use */
 };
 
 /* These must exactly match the definition from include/sys/stat.h: */
@@ -193,7 +195,7 @@ struct nuttx_stat_s
  ****************************************************************************/
 
 #ifdef __SIM__
-int           host_open(const char *pathname, int flags, nuttx_mode_t mode);
+int           host_open(const char *pathname, int flags, int mode);
 int           host_close(int fd);
 nuttx_ssize_t host_read(int fd, void *buf, nuttx_size_t count);
 nuttx_ssize_t host_write(int fd, const void *buf, nuttx_size_t count);
@@ -212,7 +214,7 @@ void          host_rewinddir(void *dirp);
 int           host_closedir(void *dirp);
 int           host_statfs(const char *path, struct nuttx_statfs_s *buf);
 int           host_unlink(const char *pathname);
-int           host_mkdir(const char *pathname, nuttx_mode_t mode);
+int           host_mkdir(const char *pathname, int mode);
 int           host_rmdir(const char *pathname);
 int           host_rename(const char *oldpath, const char *newpath);
 int           host_stat(const char *path, struct nuttx_stat_s *buf);