diff --git a/lib/libc/gen/gen-private.h b/lib/libc/gen/gen-private.h
--- a/lib/libc/gen/gen-private.h
+++ b/lib/libc/gen/gen-private.h
@@ -43,8 +43,8 @@
  */
 struct _dirdesc {
 	int	dd_fd;		/* file descriptor associated with directory */
-	long	dd_loc;		/* offset in current buffer */
-	long	dd_size;	/* amount of data returned by getdirentries */
+	size_t	dd_loc;		/* offset in current buffer */
+	size_t	dd_size;	/* amount of data returned by getdirentries */
 	char	*dd_buf;	/* data buffer */
 	int	dd_len;		/* size of data buffer */
 	off_t	dd_seek;	/* magic cookie returned by getdirentries */
diff --git a/lib/libc/gen/opendir2.c b/lib/libc/gen/opendir2.c
--- a/lib/libc/gen/opendir2.c
+++ b/lib/libc/gen/opendir2.c
@@ -264,6 +264,7 @@
 __opendir_common(int fd, int flags, bool use_current_pos)
 {
 	DIR *dirp;
+	ssize_t ret;
 	int incr;
 	int saved_errno;
 	bool unionstack;
@@ -313,10 +314,11 @@
 			 * to prime dd_seek.  This also checks if the
 			 * fd passed to fdopendir() is a directory.
 			 */
-			dirp->dd_size = _getdirentries(dirp->dd_fd,
+			ret = _getdirentries(dirp->dd_fd,
 			    dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
-			if (dirp->dd_size < 0)
+			if (ret < 0)
 				goto fail;
+			dirp->dd_size = (size_t)ret;
 			dirp->dd_flags |= __DTF_SKIPREAD;
 		} else {
 			dirp->dd_size = 0;
diff --git a/lib/libc/gen/readdir.c b/lib/libc/gen/readdir.c
--- a/lib/libc/gen/readdir.c
+++ b/lib/libc/gen/readdir.c
@@ -48,8 +48,8 @@
 _readdir_unlocked(DIR *dirp, int flags)
 {
 	struct dirent *dp;
-	long initial_seek;
-	long initial_loc = 0;
+	off_t initial_seek;
+	size_t initial_loc = 0;
 
 	for (;;) {
 		if (dirp->dd_loc >= dirp->dd_size) {
diff --git a/lib/libc/gen/telldir.h b/lib/libc/gen/telldir.h
--- a/lib/libc/gen/telldir.h
+++ b/lib/libc/gen/telldir.h
@@ -46,9 +46,9 @@
  */
 struct ddloc_mem {
 	LIST_ENTRY(ddloc_mem) loc_lqe; /* entry in list */
-	long	loc_index;	/* key associated with structure */
+	size_t	loc_index;	/* key associated with structure */
 	off_t	loc_seek;	/* magic cookie returned by getdirentries */
-	long	loc_loc;	/* offset of entry in buffer */
+	size_t	loc_loc;	/* offset of entry in buffer */
 };
 
 #ifdef __LP64__
@@ -102,7 +102,7 @@
 struct dirent	*_readdir_unlocked(DIR *, int);
 void 		_reclaim_telldir(DIR *);
 void 		_seekdir(DIR *, long);
-void		_fixtelldir(DIR *dirp, long oldseek, long oldloc);
+void		_fixtelldir(DIR *dirp, off_t oldseek, size_t oldloc);
 DIR		*__opendir_common(int, int, bool);
 
 #define	RDU_SKIP	0x0001
diff --git a/lib/libc/gen/telldir.c b/lib/libc/gen/telldir.c
--- a/lib/libc/gen/telldir.c
+++ b/lib/libc/gen/telldir.c
@@ -118,7 +118,7 @@
 	struct dirent *dp;
 	union ddloc_packed ddloc;
 	off_t loc_seek;
-	long loc_loc;
+	size_t loc_loc;
 
 	ddloc.l = loc;
 
@@ -171,7 +171,7 @@
  * fetching a new block to fix any such telldir locations.
  */
 void
-_fixtelldir(DIR *dirp, long oldseek, long oldloc)
+_fixtelldir(DIR *dirp, off_t oldseek, size_t oldloc)
 {
 	struct ddloc_mem *lp;