diff --git a/arch/sim/src/sim/up_hostfs.c b/arch/sim/src/sim/up_hostfs.c
index d0ce13a6c43..e54a2f3bc98 100644
--- a/arch/sim/src/sim/up_hostfs.c
+++ b/arch/sim/src/sim/up_hostfs.c
@@ -126,7 +126,7 @@ static void host_stat_convert(struct stat *hostbuf, struct nuttx_stat_s *buf)
  * Name: host_open
  ****************************************************************************/
 
-int host_open(const char *pathname, int flags, int mode)
+int host_open(const char *pathname, int flags, nuttx_mode_t mode)
 {
   int mapflags = 0;
 
@@ -212,11 +212,11 @@ int host_close(int fd)
  * Name: host_read
  ****************************************************************************/
 
-ssize_t host_read(int fd, void *buf, size_t count)
+nuttx_ssize_t host_read(int fd, void *buf, nuttx_size_t count)
 {
   /* Just call the read routine */
 
-  ssize_t ret = read(fd, buf, count);
+  nuttx_ssize_t ret = read(fd, buf, count);
   if (ret == -1)
     {
       ret = -errno;
@@ -229,11 +229,11 @@ ssize_t host_read(int fd, void *buf, size_t count)
  * Name: host_write
  ****************************************************************************/
 
-ssize_t host_write(int fd, const void *buf, size_t count)
+nuttx_ssize_t host_write(int fd, const void *buf, nuttx_size_t count)
 {
   /* Just call the write routine */
 
-  ssize_t ret = write(fd, buf, count);
+  nuttx_ssize_t ret = write(fd, buf, count);
   if (ret == -1)
     {
       ret = -errno;
@@ -246,12 +246,12 @@ ssize_t host_write(int fd, const void *buf, size_t count)
  * Name: host_lseek
  ****************************************************************************/
 
-off_t host_lseek(int fd, off_t offset, int whence)
+nuttx_off_t host_lseek(int fd, nuttx_off_t offset, int whence)
 {
   /* Just call the lseek routine */
 
-  off_t ret = lseek(fd, offset, whence);
-  if (ret == (off_t)-1)
+  nuttx_off_t ret = lseek(fd, offset, whence);
+  if (ret == (nuttx_off_t)-1)
     {
       ret = -errno;
     }
@@ -317,7 +317,7 @@ int host_fstat(int fd, struct nuttx_stat_s *buf)
  * Name: host_truncate
  ****************************************************************************/
 
-int host_ftruncate(int fd, off_t length)
+int host_ftruncate(int fd, nuttx_off_t length)
 {
   int ret = ftruncate(fd, length);
   if (ret < 0)
diff --git a/include/nuttx/fs/hostfs.h b/include/nuttx/fs/hostfs.h
index 9e3bfb00206..fa9ea09a796 100644
--- a/include/nuttx/fs/hostfs.h
+++ b/include/nuttx/fs/hostfs.h
@@ -110,6 +110,7 @@ typedef int32_t      nuttx_off_t;
 typedef uint32_t     nuttx_blkcnt_t;
 typedef unsigned int nuttx_mode_t;
 typedef uintptr_t    nuttx_size_t;
+typedef intptr_t     nuttx_ssize_t;
 
 /* These must match the definition in include/time.h */
 
@@ -169,16 +170,16 @@ struct nuttx_stat_s
  ****************************************************************************/
 
 #ifdef __SIM__
-int           host_open(const char *pathname, int flags, int mode);
+int           host_open(const char *pathname, int flags, nuttx_mode_t mode);
 int           host_close(int fd);
-ssize_t       host_read(int fd, void *buf, nuttx_size_t count);
-ssize_t       host_write(int fd, const void *buf, nuttx_size_t count);
-off_t         host_lseek(int fd, off_t offset, int whence);
+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);
+nuttx_off_t   host_lseek(int fd, nuttx_off_t offset, int whence);
 int           host_ioctl(int fd, int request, unsigned long arg);
 void          host_sync(int fd);
 int           host_dup(int fd);
 int           host_fstat(int fd, struct nuttx_stat_s *buf);
-int           host_ftruncate(int fd, off_t length);
+int           host_ftruncate(int fd, nuttx_off_t length);
 void         *host_opendir(const char *name);
 int           host_readdir(void *dirp, struct nuttx_dirent_s *entry);
 void          host_rewinddir(void *dirp);