diff --git a/libc/include/android/api-level.h b/libc/include/android/api-level.h
index 577fb00..1b8af78 100644
--- a/libc/include/android/api-level.h
+++ b/libc/include/android/api-level.h
@@ -124,7 +124,7 @@
  */
 int android_get_application_target_sdk_version() __INTRODUCED_IN(24);
 
-#if __ANDROID_API__ < __ANDROID_API_Q__
+#if __ANDROID_API__ < 29
 
 // android_get_device_api_level is a static inline before API level 29.
 #define __BIONIC_GET_DEVICE_API_LEVEL_INLINE static __inline
diff --git a/libc/include/android/legacy_errno_inlines.h b/libc/include/android/legacy_errno_inlines.h
index 9f116fa..fcbca13 100644
--- a/libc/include/android/legacy_errno_inlines.h
+++ b/libc/include/android/legacy_errno_inlines.h
@@ -26,12 +26,11 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _ANDROID_LEGACY_ERRNO_INLINES_H
-#define _ANDROID_LEGACY_ERRNO_INLINES_H
+#pragma once
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_L__
+#if __ANDROID_API__ < 21
 
 #include <errno.h>
 
@@ -45,4 +44,3 @@
 __END_DECLS
 
 #endif
-#endif /* _ANDROID_LEGACY_ERRNO_INLINES_H */
diff --git a/libc/include/android/legacy_fenv_inlines_arm.h b/libc/include/android/legacy_fenv_inlines_arm.h
index 5ec5582..92caa72 100644
--- a/libc/include/android/legacy_fenv_inlines_arm.h
+++ b/libc/include/android/legacy_fenv_inlines_arm.h
@@ -35,7 +35,7 @@
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_L__ && defined(__arm__)
+#if __ANDROID_API__ < 21 && defined(__arm__)
 
 #define __BIONIC_FENV_INLINE static __inline
 #include <bits/fenv_inlines_arm.h>
diff --git a/libc/include/android/legacy_fenv_inlines_mips.h b/libc/include/android/legacy_fenv_inlines_mips.h
index ccc824c..92589ed 100644
--- a/libc/include/android/legacy_fenv_inlines_mips.h
+++ b/libc/include/android/legacy_fenv_inlines_mips.h
@@ -35,7 +35,7 @@
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_L__ && (defined(__mips__) && !defined(__LP64__))
+#if __ANDROID_API__ < 21 && (defined(__mips__) && !defined(__LP64__))
 
 #define __BIONIC_FENV_INLINE static __inline
 #include <bits/fenv_inlines_mips.h>
diff --git a/libc/include/android/legacy_signal_inlines.h b/libc/include/android/legacy_signal_inlines.h
index d2c7677..90eda7d 100644
--- a/libc/include/android/legacy_signal_inlines.h
+++ b/libc/include/android/legacy_signal_inlines.h
@@ -26,12 +26,11 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _ANDROID_LEGACY_SIGNAL_INLINES_H_
-#define _ANDROID_LEGACY_SIGNAL_INLINES_H_
+#pragma once
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_L__
+#if __ANDROID_API__ < 21
 
 #include <errno.h>
 #include <signal.h>
@@ -119,6 +118,4 @@
 
 __END_DECLS
 
-#endif /* __ANDROID_API__ < __ANDROID_API_L__ */
-
-#endif /* _ANDROID_LEGACY_SIGNAL_INLINES_H_ */
+#endif
diff --git a/libc/include/android/legacy_stdlib_inlines.h b/libc/include/android/legacy_stdlib_inlines.h
index 439b486..aeb1575 100644
--- a/libc/include/android/legacy_stdlib_inlines.h
+++ b/libc/include/android/legacy_stdlib_inlines.h
@@ -26,12 +26,11 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _ANDROID_LEGACY_STDLIB_INLINES_H_
-#define _ANDROID_LEGACY_STDLIB_INLINES_H_
+#pragma once
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_K__
+#if __ANDROID_API__ < 19
 
 __BEGIN_DECLS
 
@@ -45,9 +44,11 @@
 
 __END_DECLS
 
-#endif  /* __ANDROID_API__ < __ANDROID_API_K__ */
+#endif
 
-#if __ANDROID_API__ < __ANDROID_API_L__
+
+
+#if __ANDROID_API__ < 21
 
 #include <errno.h>
 #include <float.h>
@@ -83,9 +84,11 @@
 
 __END_DECLS
 
-#endif  /* __ANDROID_API__ < __ANDROID_API_L__ */
+#endif
 
-#if __ANDROID_API__ < __ANDROID_API_O__
+
+
+#if __ANDROID_API__ < 26
 
 #include <stdlib.h>
 #include <xlocale.h>
@@ -106,6 +109,4 @@
 
 __END_DECLS
 
-#endif  /* __ANDROID_API__ < __ANDROID_API_O__ */
-
-#endif /* _ANDROID_LEGACY_STDLIB_INLINES_H_ */
+#endif
diff --git a/libc/include/android/legacy_strings_inlines.h b/libc/include/android/legacy_strings_inlines.h
index 5d63c5a..2cc2da2 100644
--- a/libc/include/android/legacy_strings_inlines.h
+++ b/libc/include/android/legacy_strings_inlines.h
@@ -26,12 +26,11 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _ANDROID_LEGACY_STRINGS_INLINES_H_
-#define _ANDROID_LEGACY_STRINGS_INLINES_H_
+#pragma once
 
 #include <sys/cdefs.h>
 
-#if defined(__i386__) && __ANDROID_API__ < __ANDROID_API_J_MR2__
+#if defined(__i386__) && __ANDROID_API__ < 18
 
 #include <strings.h>
 
@@ -43,5 +42,3 @@
 __END_DECLS
 
 #endif
-
-#endif
diff --git a/libc/include/android/legacy_sys_mman_inlines.h b/libc/include/android/legacy_sys_mman_inlines.h
index 160e6fe..04b3e97 100644
--- a/libc/include/android/legacy_sys_mman_inlines.h
+++ b/libc/include/android/legacy_sys_mman_inlines.h
@@ -30,7 +30,7 @@
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_L__
+#if __ANDROID_API__ < 21
 
 #include <errno.h>
 #include <sys/mman.h>
@@ -68,4 +68,4 @@
 
 __END_DECLS
 
-#endif  /* __ANDROID_API__ < __ANDROID_API_L__ */
+#endif
diff --git a/libc/include/android/legacy_sys_stat_inlines.h b/libc/include/android/legacy_sys_stat_inlines.h
index 9521694..d42ac01 100644
--- a/libc/include/android/legacy_sys_stat_inlines.h
+++ b/libc/include/android/legacy_sys_stat_inlines.h
@@ -26,12 +26,11 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _ANDROID_LEGACY_SYS_STAT_INLINES_H_
-#define _ANDROID_LEGACY_SYS_STAT_INLINES_H_
+#pragma once
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_L__
+#if __ANDROID_API__ < 21
 
 #include <sys/stat.h>
 
@@ -44,4 +43,3 @@
 __END_DECLS
 
 #endif
-#endif /* _ANDROID_LEGACY_SYS_STAT_INLINES_H_ */
diff --git a/libc/include/android/legacy_sys_wait_inlines.h b/libc/include/android/legacy_sys_wait_inlines.h
index 4298d76..eadc752 100644
--- a/libc/include/android/legacy_sys_wait_inlines.h
+++ b/libc/include/android/legacy_sys_wait_inlines.h
@@ -26,12 +26,11 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _ANDROID_LEGACY_SYS_WAIT_INLINES_H_
-#define _ANDROID_LEGACY_SYS_WAIT_INLINES_H_
+#pragma once
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_J_MR2__
+#if __ANDROID_API__ < 18
 
 #include <sys/syscall.h>
 #include <sys/wait.h>
@@ -45,6 +44,4 @@
 
 __END_DECLS
 
-#endif /* __ANDROID_API__ < __ANDROID_API_J_MR2__ */
-
-#endif /* _ANDROID_LEGACY_SYS_WAIT_INLINES_H_ */
+#endif
diff --git a/libc/include/android/legacy_termios_inlines.h b/libc/include/android/legacy_termios_inlines.h
index a63dba1..9ea588d 100644
--- a/libc/include/android/legacy_termios_inlines.h
+++ b/libc/include/android/legacy_termios_inlines.h
@@ -26,12 +26,11 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _ANDROID_LEGACY_TERMIOS_INLINES_H_
-#define _ANDROID_LEGACY_TERMIOS_INLINES_H_
+#pragma once
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_L__
+#if __ANDROID_API__ < 21
 
 #include <linux/termios.h>
 #include <sys/ioctl.h>
@@ -41,5 +40,3 @@
 #include <bits/termios_inlines.h>
 
 #endif
-
-#endif /* _ANDROID_LEGACY_TERMIOS_INLINES_H_ */
diff --git a/libc/include/android/legacy_threads_inlines.h b/libc/include/android/legacy_threads_inlines.h
index e73ef37..c614cd0 100644
--- a/libc/include/android/legacy_threads_inlines.h
+++ b/libc/include/android/legacy_threads_inlines.h
@@ -30,7 +30,7 @@
 
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < __ANDROID_API_R__
+#if __ANDROID_API__ < 30
 
 #define __BIONIC_THREADS_INLINE static __inline
 #include <bits/threads_inlines.h>
diff --git a/libc/include/bits/fortify/fcntl.h b/libc/include/bits/fortify/fcntl.h
index 3c5a037..7063541 100644
--- a/libc/include/bits/fortify/fcntl.h
+++ b/libc/include/bits/fortify/fcntl.h
@@ -59,7 +59,7 @@
 int open(const char* const __pass_object_size pathname, int flags)
         __overloadable
         __clang_error_if(__open_modes_useful(flags), "'open' " __open_too_few_args_error) {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     return __open_2(pathname, flags);
 #else
     return __open_real(pathname, flags);
@@ -83,7 +83,7 @@
 int openat(int dirfd, const char* const __pass_object_size pathname, int flags)
         __overloadable
         __clang_error_if(__open_modes_useful(flags), "'openat' " __open_too_few_args_error) {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     return __openat_2(dirfd, pathname, flags);
 #else
     return __openat_real(dirfd, pathname, flags);
@@ -98,7 +98,7 @@
     return __openat_real(dirfd, pathname, flags, modes);
 }
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 /* Note that open == open64, so we reuse those bits in the open64 variants below.  */
 
 __BIONIC_ERROR_FUNCTION_VISIBILITY
@@ -139,7 +139,7 @@
                            "'openat64' " __open_useless_modes_warning) {
     return openat(dirfd, pathname, flags, modes);
 }
-#endif /* __ANDROID_API__ >= __ANDROID_API_L__ */
+#endif /* __ANDROID_API__ >= 21 */
 
 #undef __open_too_many_args_error
 #undef __open_too_few_args_error
diff --git a/libc/include/bits/fortify/poll.h b/libc/include/bits/fortify/poll.h
index 30fdce4..143153c 100644
--- a/libc/include/bits/fortify/poll.h
+++ b/libc/include/bits/fortify/poll.h
@@ -44,7 +44,7 @@
     __overloadable
     __clang_error_if(__bos_unevaluated_lt(__bos(fds), sizeof(*fds) * fd_count),
                      "in call to 'poll', fd_count is larger than the given buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
   size_t bos_fds = __bos(fds);
 
   if (!__bos_fd_count_trivially_safe(bos_fds, fds, fd_count)) {
@@ -54,13 +54,13 @@
   return __call_bypassing_fortify(poll)(fds, fd_count, timeout);
 }
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 __BIONIC_FORTIFY_INLINE
 int ppoll(struct pollfd* const fds __pass_object_size, nfds_t fd_count, const struct timespec* timeout, const sigset_t* mask)
     __overloadable
     __clang_error_if(__bos_unevaluated_lt(__bos(fds), sizeof(*fds) * fd_count),
                      "in call to 'ppoll', fd_count is larger than the given buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
   size_t bos_fds = __bos(fds);
 
   if (!__bos_fd_count_trivially_safe(bos_fds, fds, fd_count)) {
@@ -69,9 +69,9 @@
 #endif
   return __call_bypassing_fortify(ppoll)(fds, fd_count, timeout, mask);
 }
-#endif /* __ANDROID_API__ >= __ANDROID_API_L__ */
+#endif /* __ANDROID_API__ >= 21 */
 
-#if __ANDROID_API__ >= __ANDROID_API_P__
+#if __ANDROID_API__ >= 28
 __BIONIC_FORTIFY_INLINE
 int ppoll64(struct pollfd* const fds __pass_object_size, nfds_t fd_count, const struct timespec* timeout, const sigset64_t* mask)
     __overloadable
@@ -86,7 +86,7 @@
 #endif
   return __call_bypassing_fortify(ppoll64)(fds, fd_count, timeout, mask);
 }
-#endif /* __ANDROID_API__ >= __ANDROID_API_P__ */
+#endif /* __ANDROID_API__ >= 28 */
 
 #undef __bos_fd_count_trivially_safe
 
diff --git a/libc/include/bits/fortify/socket.h b/libc/include/bits/fortify/socket.h
index 30fe0d7..78d4013 100644
--- a/libc/include/bits/fortify/socket.h
+++ b/libc/include/bits/fortify/socket.h
@@ -42,7 +42,7 @@
     __overloadable
     __clang_error_if(__bos_unevaluated_lt(__bos0(buf), len),
                      "'recvfrom' called with size bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_N__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 24 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
   size_t bos = __bos0(buf);
 
   if (!__bos_trivially_ge(bos, len)) {
@@ -57,7 +57,7 @@
     __overloadable
     __clang_error_if(__bos_unevaluated_lt(__bos0(buf), len),
                      "'sendto' called with size bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_N_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 25 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
   size_t bos = __bos0(buf);
 
   if (!__bos_trivially_ge(bos, len)) {
diff --git a/libc/include/bits/fortify/stat.h b/libc/include/bits/fortify/stat.h
index 43fc69c..e92e6ac 100644
--- a/libc/include/bits/fortify/stat.h
+++ b/libc/include/bits/fortify/stat.h
@@ -41,7 +41,7 @@
     __overloadable
     __enable_if(1, "")
     __clang_error_if(mode & ~0777, "'umask' called with invalid mode") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR2__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 18 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
   return __umask_chk(mode);
 #else
   return __umask_real(mode);
diff --git a/libc/include/bits/fortify/stdio.h b/libc/include/bits/fortify/stdio.h
index fb503c3..42698dd 100644
--- a/libc/include/bits/fortify/stdio.h
+++ b/libc/include/bits/fortify/stdio.h
@@ -36,7 +36,7 @@
 
 #if defined(__BIONIC_FORTIFY) && !defined(__BIONIC_NO_STDIO_FORTIFY)
 
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
 /* No diag -- clang diagnoses misuses of this on its own.  */
 __BIONIC_FORTIFY_INLINE __printflike(3, 0)
 int vsnprintf(char* const __pass_object_size dest, size_t size, const char* format, va_list ap)
@@ -57,7 +57,7 @@
                 "format string will always overflow destination buffer")
     __errorattr("format string will always overflow destination buffer");
 
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
 __BIONIC_FORTIFY_VARIADIC __printflike(2, 3)
 int sprintf(char* const __pass_object_size dest, const char* format, ...) __overloadable {
     va_list va;
@@ -90,7 +90,7 @@
                          "in call to 'fread', size * count overflows")
         __clang_error_if(__bos_unevaluated_lt(__bos0(buf), size * count),
                          "in call to 'fread', size * count is too large for the given buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_N__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 24 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_mul(bos, size, count)) {
@@ -107,7 +107,7 @@
                          "in call to 'fwrite', size * count overflows")
         __clang_error_if(__bos_unevaluated_lt(__bos0(buf), size * count),
                          "in call to 'fwrite', size * count is too large for the given buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_N__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 24 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_mul(bos, size, count)) {
@@ -124,7 +124,7 @@
         __clang_error_if(size < 0, "in call to 'fgets', size should not be negative")
         __clang_error_if(__bos_unevaluated_lt(__bos(dest), size),
                          "in call to 'fgets', size is larger than the destination buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(dest);
 
     if (!__bos_dynamic_check_impl_and(bos, >=, (size_t)size, size >= 0)) {
diff --git a/libc/include/bits/fortify/string.h b/libc/include/bits/fortify/string.h
index 7dc60f2..600ef14 100644
--- a/libc/include/bits/fortify/string.h
+++ b/libc/include/bits/fortify/string.h
@@ -40,7 +40,7 @@
 #if defined(__BIONIC_FORTIFY)
 extern void* __memrchr_real(const void*, int, size_t) __RENAME(memrchr);
 
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
 /* No diag -- clang diagnoses misuses of this on its own.  */
 __BIONIC_FORTIFY_INLINE
 void* memcpy(void* const dst __pass_object_size0, const void* src, size_t copy_amount)
@@ -64,7 +64,7 @@
 #endif
 
 #if defined(__USE_GNU)
-#if __ANDROID_API__ >= __ANDROID_API_R__
+#if __ANDROID_API__ >= 30
 __BIONIC_FORTIFY_INLINE
 void* mempcpy(void* const dst __pass_object_size0, const void* src, size_t copy_amount)
         __overloadable
@@ -78,7 +78,7 @@
 #endif
     return __builtin_mempcpy(dst, src, copy_amount);
 }
-#endif /* __ANDROID_API__ >= __ANDROID_API_R__ */
+#endif /* __ANDROID_API__ >= 30 */
 #endif /* __USE_GNU */
 
 __BIONIC_FORTIFY_INLINE
@@ -86,7 +86,7 @@
         __overloadable
         __clang_error_if(__bos_unevaluated_le(__bos(dst), __builtin_strlen(src)),
                          "'stpcpy' called with string bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_L__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 21 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos_dst = __bos(dst);
     if (!__bos_trivially_gt(bos_dst, __builtin_strlen(src))) {
         return __builtin___stpcpy_chk(dst, src, bos_dst);
@@ -100,7 +100,7 @@
         __overloadable
         __clang_error_if(__bos_unevaluated_le(__bos(dst), __builtin_strlen(src)),
                          "'strcpy' called with string bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos_dst = __bos(dst);
     if (!__bos_trivially_gt(bos_dst, __builtin_strlen(src))) {
         return __builtin___strcpy_chk(dst, src, bos_dst);
@@ -114,14 +114,14 @@
         __overloadable
         __clang_error_if(__bos_unevaluated_le(__bos(dst), __builtin_strlen(src)),
                          "'strcat' called with string bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     return __builtin___strcat_chk(dst, src, __bos(dst));
 #else
     return __builtin_strcat(dst, src);
 #endif
 }
 
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
 /* No diag -- clang diagnoses misuses of this on its own.  */
 __BIONIC_FORTIFY_INLINE
 char* strncat(char* const dst __pass_object_size, const char* src, size_t n) __overloadable {
@@ -134,7 +134,7 @@
 void* memset(void* const s __pass_object_size0, int c, size_t n) __overloadable
         /* If you're a user who wants this warning to go away: use `(&memset)(foo, bar, baz)`. */
         __clang_warning_if(c && !n, "'memset' will set 0 bytes; maybe the arguments got flipped?") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(s);
     if (!__bos_trivially_ge(bos, n)) {
         return __builtin___memset_chk(s, c, n, bos);
@@ -143,7 +143,7 @@
     return __builtin_memset(s, c, n);
 }
 
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
 __BIONIC_FORTIFY_INLINE
 void* memchr(const void* const s __pass_object_size, int c, size_t n) __overloadable {
     size_t bos = __bos(s);
@@ -167,7 +167,7 @@
 }
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_L__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 21 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
 /* No diag -- clang diagnoses misuses of this on its own.  */
 __BIONIC_FORTIFY_INLINE
 char* stpncpy(char* const dst __pass_object_size, const char* const src __pass_object_size, size_t n)
@@ -204,7 +204,7 @@
         __overloadable
         __clang_error_if(__bos_unevaluated_lt(__bos(dst), size),
                          "'strlcpy' called with size bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(dst);
 
     if (bos != __BIONIC_FORTIFY_UNKNOWN_SIZE) {
@@ -219,7 +219,7 @@
         __overloadable
         __clang_error_if(__bos_unevaluated_lt(__bos(dst), size),
                          "'strlcat' called with size bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(dst);
 
     if (bos != __BIONIC_FORTIFY_UNKNOWN_SIZE) {
@@ -231,7 +231,7 @@
 
 __BIONIC_FORTIFY_INLINE
 size_t strlen(const char* const s __pass_object_size0) __overloadable {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(s);
 
     if (!__bos_trivially_gt(bos, __builtin_strlen(s))) {
@@ -243,7 +243,7 @@
 
 __BIONIC_FORTIFY_INLINE
 char* strchr(const char* const s __pass_object_size, int c) __overloadable {
-#if  __ANDROID_API__ >= __ANDROID_API_J_MR2__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if  __ANDROID_API__ >= 18 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(s);
 
     if (bos != __BIONIC_FORTIFY_UNKNOWN_SIZE) {
@@ -255,7 +255,7 @@
 
 __BIONIC_FORTIFY_INLINE
 char* strrchr(const char* const s __pass_object_size, int c) __overloadable {
-#if  __ANDROID_API__ >= __ANDROID_API_J_MR2__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if  __ANDROID_API__ >= 18 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(s);
 
     if (bos != __BIONIC_FORTIFY_UNKNOWN_SIZE) {
@@ -265,7 +265,7 @@
     return __builtin_strrchr(s, c);
 }
 
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
 #if defined(__cplusplus)
 extern "C++" {
 __BIONIC_FORTIFY_INLINE
@@ -284,6 +284,6 @@
     return __memrchr_fortify(s, c, n);
 }
 #endif
-#endif /* __ANDROID_API__ >= __ANDROID_API_M__ */
+#endif /* __ANDROID_API__ >= 23 */
 
 #endif /* defined(__BIONIC_FORTIFY) */
diff --git a/libc/include/bits/fortify/strings.h b/libc/include/bits/fortify/strings.h
index 1ebaf39..65fc5f1 100644
--- a/libc/include/bits/fortify/strings.h
+++ b/libc/include/bits/fortify/strings.h
@@ -33,7 +33,7 @@
         __overloadable
         __clang_error_if(__bos_unevaluated_lt(__bos0(dst), len),
                          "'bcopy' called with size bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(dst);
     if (!__bos_trivially_ge(bos, len)) {
         __builtin___memmove_chk(dst, src, len, bos);
@@ -48,7 +48,7 @@
         __overloadable
         __clang_error_if(__bos_unevaluated_lt(__bos0(b), len),
                          "'bzero' called with size bigger than buffer") {
-#if __ANDROID_API__ >= __ANDROID_API_J_MR1__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 17 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(b);
     if (!__bos_trivially_ge(bos, len)) {
         __builtin___memset_chk(b, 0, len, bos);
diff --git a/libc/include/bits/fortify/unistd.h b/libc/include/bits/fortify/unistd.h
index f1580ce..49a3946 100644
--- a/libc/include/bits/fortify/unistd.h
+++ b/libc/include/bits/fortify/unistd.h
@@ -73,7 +73,7 @@
 char* getcwd(char* const __pass_object_size buf, size_t size)
         __overloadable
         __error_if_overflows_objectsize(size, __bos(buf), getcwd) {
-#if __ANDROID_API__ >= __ANDROID_API_N__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 24 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(buf);
 
     if (!__bos_trivially_ge(bos, size)) {
@@ -89,7 +89,7 @@
         __overloadable
         __error_if_overflows_ssizet(count, pread)
         __error_if_overflows_objectsize(count, __bos0(buf), pread) {
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, count)) {
@@ -105,7 +105,7 @@
         __overloadable
         __error_if_overflows_ssizet(count, pread64)
         __error_if_overflows_objectsize(count, __bos0(buf), pread64) {
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, count)) {
@@ -121,7 +121,7 @@
         __overloadable
         __error_if_overflows_ssizet(count, pwrite)
         __error_if_overflows_objectsize(count, __bos0(buf), pwrite) {
-#if __ANDROID_API__ >= __ANDROID_API_N__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 24 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, count)) {
@@ -137,7 +137,7 @@
         __overloadable
         __error_if_overflows_ssizet(count, pwrite64)
         __error_if_overflows_objectsize(count, __bos0(buf), pwrite64) {
-#if __ANDROID_API__ >= __ANDROID_API_N__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 24 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, count)) {
@@ -152,7 +152,7 @@
         __overloadable
         __error_if_overflows_ssizet(count, read)
         __error_if_overflows_objectsize(count, __bos0(buf), read) {
-#if __ANDROID_API__ >= __ANDROID_API_L__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 21 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, count)) {
@@ -167,7 +167,7 @@
         __overloadable
         __error_if_overflows_ssizet(count, write)
         __error_if_overflows_objectsize(count, __bos0(buf), write) {
-#if __ANDROID_API__ >= __ANDROID_API_N__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 24 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos0(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, count)) {
@@ -182,7 +182,7 @@
         __overloadable
         __error_if_overflows_ssizet(size, readlink)
         __error_if_overflows_objectsize(size, __bos(buf), readlink) {
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, size)) {
@@ -192,13 +192,13 @@
     return __call_bypassing_fortify(readlink)(path, buf, size);
 }
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 __BIONIC_FORTIFY_INLINE
 ssize_t readlinkat(int dirfd, const char* path, char* const __pass_object_size buf, size_t size)
         __overloadable
         __error_if_overflows_ssizet(size, readlinkat)
         __error_if_overflows_objectsize(size, __bos(buf), readlinkat) {
-#if __ANDROID_API__ >= __ANDROID_API_M__ && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
+#if __ANDROID_API__ >= 23 && __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED
     size_t bos = __bos(buf);
 
     if (!__bos_trivially_ge_no_overflow(bos, size)) {
@@ -207,7 +207,7 @@
 #endif
     return __call_bypassing_fortify(readlinkat)(dirfd, path, buf, size);
 }
-#endif /* __ANDROID_API__ >= __ANDROID_API_L__ */
+#endif /* __ANDROID_API__ >= 21 */
 
 #undef __bos_trivially_ge_no_overflow
 #undef __enable_if_no_overflow_ssizet
diff --git a/libc/include/bits/pthread_types.h b/libc/include/bits/pthread_types.h
index a173e3c..f359696 100644
--- a/libc/include/bits/pthread_types.h
+++ b/libc/include/bits/pthread_types.h
@@ -26,8 +26,7 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _BITS_PTHREAD_TYPES_H_
-#define _BITS_PTHREAD_TYPES_H_
+#pragma once
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
@@ -44,7 +43,7 @@
 #endif
 } pthread_attr_t;
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 typedef struct {
 #if defined(__LP64__)
   int64_t __private[4];
@@ -54,7 +53,7 @@
 } pthread_barrier_t;
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 typedef int pthread_barrierattr_t;
 #endif
 
@@ -92,7 +91,7 @@
 
 typedef long pthread_rwlockattr_t;
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 typedef struct {
 #if defined(__LP64__)
   int64_t __private;
@@ -103,5 +102,3 @@
 #endif
 
 typedef long pthread_t;
-
-#endif
diff --git a/libc/include/bits/threads_inlines.h b/libc/include/bits/threads_inlines.h
index 8f2beb0..afaed64 100644
--- a/libc/include/bits/threads_inlines.h
+++ b/libc/include/bits/threads_inlines.h
@@ -103,7 +103,7 @@
   return __bionic_thrd_error(pthread_mutex_lock(__mtx));
 }
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 __BIONIC_THREADS_INLINE int mtx_timedlock(mtx_t* __mtx,
                                           const struct timespec* __timeout) {
   return __bionic_thrd_error(pthread_mutex_timedlock(__mtx, __timeout));
diff --git a/libc/include/ctype.h b/libc/include/ctype.h
index e7df299..61fb476 100644
--- a/libc/include/ctype.h
+++ b/libc/include/ctype.h
@@ -124,7 +124,7 @@
  */
 int _toupper(int __ch) __INTRODUCED_IN(21);
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 /** Like isalnum but with an ignored `locale_t`. */
 int isalnum_l(int __ch, locale_t __l) __INTRODUCED_IN(21);
 /** Like isalpha but with an ignored `locale_t`. */
diff --git a/libc/include/fcntl.h b/libc/include/fcntl.h
index c45c91f..23a58d6 100644
--- a/libc/include/fcntl.h
+++ b/libc/include/fcntl.h
@@ -66,7 +66,7 @@
 /** Flag for open(). */
 #define O_RSYNC O_SYNC
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 /** Flag for splice(). */
 #define SPLICE_F_MOVE 1
 /** Flag for splice(). */
@@ -77,7 +77,7 @@
 #define SPLICE_F_GIFT 8
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_O__
+#if __ANDROID_API__ >= 26
 /** Flag for sync_file_range(). */
 #define SYNC_FILE_RANGE_WAIT_BEFORE 1
 /** Flag for sync_file_range(). */
diff --git a/libc/include/fenv.h b/libc/include/fenv.h
index 90ac805..fd78a48 100644
--- a/libc/include/fenv.h
+++ b/libc/include/fenv.h
@@ -44,7 +44,7 @@
 __BEGIN_DECLS
 
 // fenv was always available on x86.
-#if __ANDROID_API__ >= __ANDROID_API_L__ || defined(__i386__)
+#if __ANDROID_API__ >= 21 || defined(__i386__)
 int feclearexcept(int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_MIPS(21) __INTRODUCED_IN_X86(9);
 int fegetexceptflag(fexcept_t* __flag_ptr, int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_MIPS(21) __INTRODUCED_IN_X86(9);
 int feraiseexcept(int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_MIPS(21) __INTRODUCED_IN_X86(9);
diff --git a/libc/include/netinet/in.h b/libc/include/netinet/in.h
index 1c9961c..7f00a7a 100644
--- a/libc/include/netinet/in.h
+++ b/libc/include/netinet/in.h
@@ -26,8 +26,7 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _NETINET_IN_H_
-#define _NETINET_IN_H_
+#pragma once
 
 #include <endian.h>
 #include <netinet/in6.h>
@@ -46,14 +45,12 @@
 
 int bindresvport(int __fd, struct sockaddr_in* __sin);
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 extern const struct in6_addr in6addr_any __INTRODUCED_IN(24);
 extern const struct in6_addr in6addr_loopback __INTRODUCED_IN(24);
 #else
 static const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
 static const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
-#endif /* __ANDROID_API__ >= __ANDROID_API_N__ */
+#endif
 
 __END_DECLS
-
-#endif
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index b549871..331e92c 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -54,7 +54,7 @@
 #define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP { { ((PTHREAD_MUTEX_ERRORCHECK & 3) << 14) } }
 
 #define PTHREAD_COND_INITIALIZER  { { 0 } }
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 #define PTHREAD_COND_INITIALIZER_MONOTONIC_NP  { { 1 << 1 } }
 #endif
 
@@ -67,7 +67,7 @@
 
 #define PTHREAD_ONCE_INIT 0
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 #define PTHREAD_BARRIER_SERIAL_THREAD -1
 #endif
 
@@ -254,20 +254,20 @@
 int pthread_rwlock_unlock(pthread_rwlock_t* __rwlock);
 int pthread_rwlock_wrlock(pthread_rwlock_t* __rwlock);
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 int pthread_barrierattr_init(pthread_barrierattr_t* __attr) __INTRODUCED_IN(24);
 int pthread_barrierattr_destroy(pthread_barrierattr_t* __attr) __INTRODUCED_IN(24);
 int pthread_barrierattr_getpshared(const pthread_barrierattr_t* __attr, int* __shared) __INTRODUCED_IN(24);
 int pthread_barrierattr_setpshared(pthread_barrierattr_t* __attr, int __shared) __INTRODUCED_IN(24);
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 int pthread_barrier_init(pthread_barrier_t* __barrier, const pthread_barrierattr_t* __attr, unsigned __count) __INTRODUCED_IN(24);
 int pthread_barrier_destroy(pthread_barrier_t* __barrier) __INTRODUCED_IN(24);
 int pthread_barrier_wait(pthread_barrier_t* __barrier) __INTRODUCED_IN(24);
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_N__
+#if __ANDROID_API__ >= 24
 int pthread_spin_destroy(pthread_spinlock_t* __spinlock) __INTRODUCED_IN(24);
 int pthread_spin_init(pthread_spinlock_t* __spinlock, int __shared) __INTRODUCED_IN(24);
 int pthread_spin_lock(pthread_spinlock_t* __spinlock) __INTRODUCED_IN(24);
diff --git a/libc/include/signal.h b/libc/include/signal.h
index cd11656..532e4a5 100644
--- a/libc/include/signal.h
+++ b/libc/include/signal.h
@@ -64,7 +64,7 @@
 
 int siginterrupt(int __signal, int __flag);
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 sighandler_t signal(int __signal, sighandler_t __handler) __INTRODUCED_IN(21);
 int sigaddset(sigset_t* __set, int __signal) __INTRODUCED_IN(21);
 int sigaddset64(sigset64_t* __set, int __signal) __INTRODUCED_IN(28);
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index 6632c01..1bf578c 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -46,7 +46,7 @@
 
 #include <bits/seek_constants.h>
 
-#if __ANDROID_API__ < __ANDROID_API_N__
+#if __ANDROID_API__ < 24
 #include <bits/struct_file.h>
 #endif
 
@@ -58,7 +58,7 @@
 struct __sFILE;
 typedef struct __sFILE FILE;
 
-#if __ANDROID_API__ >= __ANDROID_API_M__
+#if __ANDROID_API__ >= 23
 extern FILE* stdin __INTRODUCED_IN(23);
 extern FILE* stdout __INTRODUCED_IN(23);
 extern FILE* stderr __INTRODUCED_IN(23);
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index b66e3c6..dc7b694 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -43,7 +43,7 @@
 
 __noreturn void abort(void);
 __noreturn void exit(int __status);
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 __noreturn void _Exit(int __status) __INTRODUCED_IN(21);
 #else
 __noreturn void _Exit(int) __RENAME(_exit);
@@ -167,7 +167,7 @@
 
 size_t wcstombs(char* __dst, const wchar_t* __src, size_t __n);
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 size_t __ctype_get_mb_cur_max(void) __INTRODUCED_IN(21);
 #define MB_CUR_MAX __ctype_get_mb_cur_max()
 #else
@@ -183,7 +183,7 @@
 #include <bits/fortify/stdlib.h>
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_K__
+#if __ANDROID_API__ >= 19
 int abs(int __x) __attribute_const__ __INTRODUCED_IN(19);
 long labs(long __x) __attribute_const__ __INTRODUCED_IN(19);
 long long llabs(long long __x) __attribute_const__ __INTRODUCED_IN(19);
@@ -191,7 +191,7 @@
 // Implemented as static inlines before 19.
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 float strtof(const char* __s, char** __end_ptr) __INTRODUCED_IN(21);
 double atof(const char* __s) __attribute_pure__ __INTRODUCED_IN(21);
 int rand(void) __INTRODUCED_IN(21);
@@ -207,7 +207,7 @@
 // Implemented as static inlines before 21.
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_O__
+#if __ANDROID_API__ >= 26
 double strtod_l(const char* __s, char** __end_ptr, locale_t __l) __INTRODUCED_IN(26);
 float strtof_l(const char* __s, char** __end_ptr, locale_t __l) __INTRODUCED_IN(26);
 long strtol_l(const char* __s, char** __end_ptr, int, locale_t __l) __INTRODUCED_IN(26);
diff --git a/libc/include/string.h b/libc/include/string.h
index 25f6673..0cc5611 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -119,7 +119,7 @@
 int strcoll(const char* __lhs, const char* __rhs) __attribute_pure__;
 size_t strxfrm(char* __dst, const char* __src, size_t __n);
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 int strcoll_l(const char* __lhs, const char* __rhs, locale_t __l) __attribute_pure__ __INTRODUCED_IN(21);
 size_t strxfrm_l(char* __dst, const char* __src, size_t __n, locale_t __l) __INTRODUCED_IN(21);
 #else
diff --git a/libc/include/strings.h b/libc/include/strings.h
index d6ee1c8..08c2326 100644
--- a/libc/include/strings.h
+++ b/libc/include/strings.h
@@ -63,7 +63,7 @@
   __builtin_memset(b, 0, len);
 }
 
-#if !defined(__i386__) || __ANDROID_API__ >= __ANDROID_API_J_MR2__
+#if !defined(__i386__) || __ANDROID_API__ >= 18
 /**
  * [ffs(3)](http://man7.org/linux/man-pages/man3/ffs.3.html) finds the first set bit in `__i`.
  *
diff --git a/libc/include/sys/epoll.h b/libc/include/sys/epoll.h
index a213a90..3745737 100644
--- a/libc/include/sys/epoll.h
+++ b/libc/include/sys/epoll.h
@@ -51,7 +51,7 @@
  * https://github.com/android-ndk/ndk/issues/302
  * https://github.com/android-ndk/ndk/issues/394
  */
-#if __ANDROID_API__ < __ANDROID_API_L__ && defined(EPOLL_CLOEXEC)
+#if __ANDROID_API__ < 21 && defined(EPOLL_CLOEXEC)
 #undef EPOLL_CLOEXEC
 #endif
 
diff --git a/libc/include/sys/inotify.h b/libc/include/sys/inotify.h
index 32e16d9..37fbf99 100644
--- a/libc/include/sys/inotify.h
+++ b/libc/include/sys/inotify.h
@@ -48,7 +48,7 @@
  *
  * https://github.com/android-ndk/ndk/issues/394
  */
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 #define IN_CLOEXEC O_CLOEXEC
 #define IN_NONBLOCK O_NONBLOCK
 #endif
diff --git a/libc/include/sys/mman.h b/libc/include/sys/mman.h
index 3b83229..fe4ea7f 100644
--- a/libc/include/sys/mman.h
+++ b/libc/include/sys/mman.h
@@ -54,7 +54,7 @@
 void* mmap(void* __addr, size_t __size, int __prot, int __flags, int __fd, off_t __offset);
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 /**
  * mmap64() is a variant of mmap() that takes a 64-bit offset even on LP32.
  *
@@ -173,7 +173,7 @@
 
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_M__
+#if __ANDROID_API__ >= 23
 
 /*
  * Some third-party code uses the existence of POSIX_MADV_NORMAL to detect the
diff --git a/libc/include/sys/select.h b/libc/include/sys/select.h
index 1ee8d2a..79fc28d 100644
--- a/libc/include/sys/select.h
+++ b/libc/include/sys/select.h
@@ -79,7 +79,7 @@
 #define __FD_SET(fd, set) (__FDS_BITS(fd_set*,set)[__FDELT(fd)] |= __FDMASK(fd))
 #define __FD_ISSET(fd, set) ((__FDS_BITS(const fd_set*,set)[__FDELT(fd)] & __FDMASK(fd)) != 0)
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 
 /** Removes `fd` from the given set. Use <poll.h> instead. */
 #define FD_CLR(fd, set) __FD_CLR_chk(fd, set, __bos(set))
diff --git a/libc/include/sys/socket.h b/libc/include/sys/socket.h
index e54dd65..e2acab7 100644
--- a/libc/include/sys/socket.h
+++ b/libc/include/sys/socket.h
@@ -112,7 +112,7 @@
    ? (struct cmsghdr*) (msg)->msg_control : (struct cmsghdr*) NULL)
 #define CMSG_OK(mhdr, cmsg) ((cmsg)->cmsg_len >= sizeof(struct cmsghdr) &&   (cmsg)->cmsg_len <= (unsigned long)   ((mhdr)->msg_controllen -   ((char*)(cmsg) - (char*)(mhdr)->msg_control)))
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 struct cmsghdr* __cmsg_nxthdr(struct msghdr* __msg, struct cmsghdr* __cmsg) __INTRODUCED_IN(21);
 #else
 /* TODO(danalbert): Move this into libandroid_support. */
@@ -127,7 +127,7 @@
   }
   return ptr;
 }
-#endif /* __ANDROID_API__ >= __ANDROID_API_L__ */
+#endif
 
 #define SCM_RIGHTS 0x01
 #define SCM_CREDENTIALS 0x02
diff --git a/libc/include/sys/stat.h b/libc/include/sys/stat.h
index 79113b6..d8e92d9 100644
--- a/libc/include/sys/stat.h
+++ b/libc/include/sys/stat.h
@@ -171,7 +171,7 @@
 #include <bits/fortify/stat.h>
 #endif
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 int mkfifo(const char* __path, mode_t __mode) __INTRODUCED_IN(21);
 #else
 // Implemented as a static inline before 21.
diff --git a/libc/include/sys/wait.h b/libc/include/sys/wait.h
index 106946b..8c0655f 100644
--- a/libc/include/sys/wait.h
+++ b/libc/include/sys/wait.h
@@ -40,7 +40,7 @@
 
 pid_t wait(int* __status);
 pid_t waitpid(pid_t __pid, int* __status, int __options);
-#if __ANDROID_API__ >= __ANDROID_API_J_MR2__
+#if __ANDROID_API__ >= 18
 pid_t wait4(pid_t __pid, int* __status, int __options, struct rusage* __rusage) __INTRODUCED_IN(18);
 #else
 // Implemented as a static inline before 18.
diff --git a/libc/include/termios.h b/libc/include/termios.h
index 0fd5c95..8eca96e 100644
--- a/libc/include/termios.h
+++ b/libc/include/termios.h
@@ -40,7 +40,7 @@
 
 __BEGIN_DECLS
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 // This file is implemented as static inlines before API level 21.
 
 /**
diff --git a/libc/include/threads.h b/libc/include/threads.h
index 752761d..1b00b8f 100644
--- a/libc/include/threads.h
+++ b/libc/include/threads.h
@@ -78,7 +78,7 @@
 
 __BEGIN_DECLS
 
-#if __ANDROID_API__ >= __ANDROID_API_R__
+#if __ANDROID_API__ >= 30
 // This file is implemented as static inlines before API level 30.
 
 /** Uses `__flag` to ensure that `__function` is called exactly once. */
diff --git a/libc/include/time.h b/libc/include/time.h
index a7a6fe5..0db14ff 100644
--- a/libc/include/time.h
+++ b/libc/include/time.h
@@ -78,7 +78,7 @@
 char* strptime_l(const char* __s, const char* __fmt, struct tm* __tm, locale_t __l) __strftimelike(2) __INTRODUCED_IN(28);
 
 size_t strftime(char* __buf, size_t __n, const char* __fmt, const struct tm* __tm) __strftimelike(3);
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 size_t strftime_l(char* __buf, size_t __n, const char* __fmt, const struct tm* __tm, locale_t __l) __strftimelike(3) __INTRODUCED_IN(21);
 #else
 // Implemented as static inline before 21.
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 7c01549..e4afd8e 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -282,7 +282,7 @@
 
 int acct(const char* __path);
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 int getpagesize(void) __INTRODUCED_IN(21);
 #else
 static __inline__ int getpagesize(void) {
diff --git a/libc/include/wchar.h b/libc/include/wchar.h
index f33af5f..f0966de 100644
--- a/libc/include/wchar.h
+++ b/libc/include/wchar.h
@@ -121,7 +121,7 @@
 int wprintf(const wchar_t* __fmt, ...);
 int wscanf(const wchar_t* __fmt, ...);
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 long long wcstoll_l(const wchar_t* __s, wchar_t** __end_ptr, int __base, locale_t __l) __INTRODUCED_IN(21);
 unsigned long long wcstoull_l(const wchar_t* __s, wchar_t** __end_ptr, int __base, locale_t __l) __INTRODUCED_IN(21);
 long double wcstold_l(const wchar_t* __s, wchar_t** __end_ptr, locale_t __l) __INTRODUCED_IN(21);
diff --git a/libc/include/wctype.h b/libc/include/wctype.h
index 18f5c4b..58510ae 100644
--- a/libc/include/wctype.h
+++ b/libc/include/wctype.h
@@ -35,7 +35,7 @@
 
 __BEGIN_DECLS
 
-#if __ANDROID_API__ >= __ANDROID_API_L__
+#if __ANDROID_API__ >= 21
 int iswalnum_l(wint_t __wc, locale_t __l) __INTRODUCED_IN(21);
 int iswalpha_l(wint_t __wc, locale_t __l) __INTRODUCED_IN(21);
 int iswblank_l(wint_t __wc, locale_t __l) __INTRODUCED_IN(21);