diff --git a/sysdeps/posix/opendir.c b/sysdeps/posix/opendir.c
index d925804..dea23b2 100644
--- a/sysdeps/posix/opendir.c
+++ b/sysdeps/posix/opendir.c
@@ -15,24 +15,13 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <assert.h>
-#include <errno.h>
-#include <limits.h>
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdlib.h>
 #include <dirent.h>
 #include <fcntl.h>
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <string.h>
-
-#include <dirstream.h>
+#include <errno.h>
+#include <stdio.h>	/* For BUFSIZ.  */
+#include <sys/param.h>	/* For MIN and MAX.  */
+
 #include <not-cancel.h>
-#include <kernel-features.h>
 
 /* The st_blksize value of the directory is used as a hint for the
    size of the buffer which receives struct dirent values from the
@@ -40,49 +29,8 @@
    file system provides a bogus value.  */
 #define MAX_DIR_BUFFER_SIZE 1048576U
 
-/* opendir() must not accidentally open something other than a directory.
-   Some OS's have kernel support for that, some don't.  In the worst
-   case we have to stat() before the open() AND fstat() after.
-
-   We have to test at runtime for kernel support since libc may have
-   been compiled with different headers to the kernel it's running on.
-   This test can't be done reliably in the general case.  We'll use
-   /dev/null, which if it's not a device lots of stuff will break, as
-   a guinea pig.  It may be missing in chroot environments, so we
-   make sure to fail safe. */
-#ifdef O_DIRECTORY
-# ifdef O_DIRECTORY_WORKS
-#  define o_directory_works 1
-#  define tryopen_o_directory() while (1) /* This must not be called.  */
-# else
-static int o_directory_works;
-
-static void
-tryopen_o_directory (void)
-{
-  int serrno = errno;
-  int x = __open_nocancel ("/dev/null", O_RDONLY|O_NDELAY|O_DIRECTORY);
-
-  if (x >= 0)
-    {
-      __close_nocancel_nostatus (x);
-      o_directory_works = -1;
-    }
-  else if (errno != ENOTDIR)
-    o_directory_works = -1;
-  else
-    o_directory_works = 1;
-
-  __set_errno (serrno);
-}
-# endif
-# define EXTRA_FLAGS O_DIRECTORY
-#else
-# define EXTRA_FLAGS 0
-#endif
-
 enum {
-  opendir_oflags = O_RDONLY|O_NDELAY|EXTRA_FLAGS|O_LARGEFILE|O_CLOEXEC
+  opendir_oflags = O_RDONLY|O_NDELAY|O_DIRECTORY|O_LARGEFILE|O_CLOEXEC
 };
 
 static bool
@@ -98,21 +46,6 @@ invalid_name (const char *name)
   return false;
 }
 
-
-static bool
-need_isdir_precheck (void)
-{
-#ifdef O_DIRECTORY
-  /* Test whether O_DIRECTORY works.  */
-  if (o_directory_works == 0)
-    tryopen_o_directory ();
-
-  /* We can skip the expensive `stat' call if O_DIRECTORY works.  */
-  return o_directory_works < 0;
-#endif
-  return true;
-}
-
 static DIR *
 opendir_tail (int fd)
 {
@@ -144,22 +77,6 @@ __opendirat (int dfd, const char *name)
   if (__glibc_unlikely (invalid_name (name)))
     return NULL;
 
-  if (need_isdir_precheck ())
-    {
-      /* We first have to check whether the name is for a directory.  We
-	 cannot do this after the open() call since the open/close operation
-	 performed on, say, a tape device might have undesirable effects.  */
-      struct stat64 statbuf;
-      if (__glibc_unlikely (__fxstatat64 (_STAT_VER, dfd, name,
-					  &statbuf, 0) < 0))
-	return NULL;
-      if (__glibc_unlikely (! S_ISDIR (statbuf.st_mode)))
-	{
-	  __set_errno (ENOTDIR);
-	  return NULL;
-	}
-    }
-
   return opendir_tail (__openat_nocancel (dfd, name, opendir_oflags));
 }
 #endif
@@ -172,21 +89,6 @@ __opendir (const char *name)
   if (__glibc_unlikely (invalid_name (name)))
     return NULL;
 
-  if (need_isdir_precheck ())
-    {
-      /* We first have to check whether the name is for a directory.  We
-	 cannot do this after the open() call since the open/close operation
-	 performed on, say, a tape device might have undesirable effects.  */
-      struct stat64 statbuf;
-      if (__glibc_unlikely (__xstat64 (_STAT_VER, name, &statbuf) < 0))
-	return NULL;
-      if (__glibc_unlikely (! S_ISDIR (statbuf.st_mode)))
-	{
-	  __set_errno (ENOTDIR);
-	  return NULL;
-	}
-    }
-
   return opendir_tail (__open_nocancel (name, opendir_oflags));
 }
 weak_alias (__opendir, opendir)
diff --git a/sysdeps/unix/sysv/linux/opendir.c b/sysdeps/unix/sysv/linux/opendir.c
deleted file mode 100644
index 2677253..0000000
--- a/sysdeps/unix/sysv/linux/opendir.c
+++ /dev/null
@@ -1,20 +0,0 @@
-/* Copyright (C) 2000-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#define O_DIRECTORY_WORKS	1
-
-#include <sysdeps/posix/opendir.c>
