diff --git a/libc/kernel/common/linux/const.h b/libc/kernel/common/linux/const.h
new file mode 100644
index 0000000..d348300
--- /dev/null
+++ b/libc/kernel/common/linux/const.h
@@ -0,0 +1,31 @@
+/****************************************************************************
+ ****************************************************************************
+ ***
+ ***   This header was automatically generated from a Linux kernel header
+ ***   of the same name, to make information necessary for userspace to
+ ***   call into the kernel available to libc.  It contains only constants,
+ ***   structures, and macros generated from the original header, and thus,
+ ***   contains no copyrightable information.
+ ***
+ ***   To edit the content of this header, modify the corresponding
+ ***   source file (e.g. under external/kernel-headers/original/) then
+ ***   run bionic/libc/kernel/tools/update_all.py
+ ***
+ ***   Any manual change here will be lost the next time this script will
+ ***   be run. You've been warned!
+ ***
+ ****************************************************************************
+ ****************************************************************************/
+#ifndef _LINUX_CONST_H
+#define _LINUX_CONST_H
+#ifdef __ASSEMBLY__
+#define _AC(X,Y) X
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#define _AT(T,X) X
+#else
+#define __AC(X,Y) (X##Y)
+#define _AC(X,Y) __AC(X,Y)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#define _AT(T,X) ((T)(X))
+#endif
+#endif
diff --git a/libc/kernel/common/linux/posix_types.h b/libc/kernel/common/linux/posix_types.h
index d629e22..c197519 100644
--- a/libc/kernel/common/linux/posix_types.h
+++ b/libc/kernel/common/linux/posix_types.h
@@ -19,21 +19,11 @@
 #ifndef _LINUX_POSIX_TYPES_H
 #define _LINUX_POSIX_TYPES_H
 #include <linux/stddef.h>
-#undef __NFDBITS
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define __NFDBITS (8 * sizeof(unsigned long))
 #undef __FD_SETSIZE
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define __FD_SETSIZE 1024
-#undef __FDSET_LONGS
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define __FDSET_LONGS (__FD_SETSIZE/__NFDBITS)
-#undef __FDELT
-#define __FDELT(d) ((d) / __NFDBITS)
-#undef __FDMASK
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define __FDMASK(d) (1UL << ((d) % __NFDBITS))
 typedef struct {
- unsigned long fds_bits [__FDSET_LONGS];
+ unsigned long fds_bits[__FD_SETSIZE / (8 * sizeof(long))];
 } __kernel_fd_set;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 typedef void (*__kernel_sighandler_t)(int);