diff --git a/fs/vfs/vfs.h b/fs/vfs/vfs.h
index 2a99c69833c326ab8cba741fe1a1d8adfb621649..f9ddfd51b1e770899d9c6182545c5aadcc787f86 100755
--- a/fs/vfs/vfs.h
+++ b/fs/vfs/vfs.h
@@ -72,7 +72,6 @@ extern int vfs_debug;
  */
 struct task {
 	struct list_head t_link;	/* hash link */
-	task_t	    t_taskid;		/* task id */
 	char 	    t_cwd[PATH_MAX];	/* current working directory */
 	file_t	    t_cwdfp;		/* directory for cwd */
 	file_t	    t_ofile[OPEN_MAX];	/* pointers to file structures of open files */
@@ -129,7 +128,7 @@ void	 task_delfd(struct task *t, int fd);
 
 int	 task_conv(struct task *t, const char *path, int mode, char *full);
 
-int	 sec_file_permission(task_t task, char *path, int mode);
+//int	 sec_file_permission(task_t task, char *path, int mode);
 int	 sec_vnode_permission(char *path);
 
 int	 namei(char *path, vnode_t *vpp);
diff --git a/fs/vfs/vfs_mount.c b/fs/vfs/vfs_mount.c
index c75d985fc8fb47c0980ead8723c27985c49058bd..d24c08b62eb66330eb3d4f3e52097d0de3ad4e53 100755
--- a/fs/vfs/vfs_mount.c
+++ b/fs/vfs/vfs_mount.c
@@ -86,7 +86,7 @@ sys_mount(char *dev, char *dir, char *fsname, int flags, void *data)
 	const struct vfssw *fs;
 	mount_t mp;
 	list_t head, n;
-	device_t device;
+	struct device *device;
 	vnode_t vp, vp_covered;
 	int error;
 
@@ -253,7 +253,7 @@ sys_umount(char *path)
 
 #if HAVE_DEVICES
 	if (mp->m_dev)
-		device_close((device_t)mp->m_dev);
+		device_close(mp->m_dev);
 #endif
 	free(mp);
  out:
diff --git a/fs/vfs/vfs_task.c b/fs/vfs/vfs_task.c
index be17dbb4c7041435822508ee8a8471e7ea64bd48..bdf1a344a8c0bebc8d22b5255c8d1b7818e640d9 100755
--- a/fs/vfs/vfs_task.c
+++ b/fs/vfs/vfs_task.c
@@ -51,7 +51,6 @@ task_alloc(struct task **pt)
 	if (!(t = malloc(sizeof(struct task))))
 		return ENOMEM;
 	memset(t, 0, sizeof(struct task));
-	t->t_taskid = 0;
 	strlcpy(t->t_cwd, "/", sizeof(t->t_cwd));
 	mutex_init(&t->t_lock);
 
diff --git a/include/osv/prex.h b/include/osv/prex.h
index 6bebac8b31a12adcf1d74995ad585a8e9a8fbbd7..133aae1eb305ab5df888d7ae6c4c9e9aa2aa5461 100644
--- a/include/osv/prex.h
+++ b/include/osv/prex.h
@@ -7,7 +7,6 @@
 
 __BEGIN_DECLS
 
-#define TASK_NULL	  ((task_t)0)
 #define	BSIZE	512		/* size of secondary block (bytes) */
 
 /*
@@ -26,13 +25,6 @@ __BEGIN_DECLS
 #define round_page(x)	(((x) + PAGE_MASK) & ~PAGE_MASK)
 
 
-typedef unsigned long   object_t;
-typedef unsigned long   task_t;
-typedef unsigned long   thread_t;
-typedef unsigned long   cond_t;
-typedef unsigned long   sem_t;
-typedef unsigned long   device_t;
-
 size_t strlcat(char *dst, const char *src, size_t siz);
 size_t strlcpy(char *dst, const char *src, size_t siz);