diff --git a/libc/include/bits/posix_limits.h b/libc/include/bits/posix_limits.h
index e5846d6..2688cc5 100644
--- a/libc/include/bits/posix_limits.h
+++ b/libc/include/bits/posix_limits.h
@@ -70,7 +70,7 @@
 #define _POSIX_SHELL 1 /* system. */
 #define _POSIX_SPAWN __BIONIC_POSIX_FEATURE_SINCE(28) /* <spawn.h> */
 #define _POSIX_SPIN_LOCKS __BIONIC_POSIX_FEATURE_SINCE(24) /* pthread_spin_*. */
-#define _POSIX_SPORADIC_SERVER _POSIX_VERSION /* sched_setparam/sched_setscheduler. */
+#define _POSIX_SPORADIC_SERVER __BIONIC_POSIX_FEATURE_MISSING /* No SCHED_SPORADIC. */
 #define _POSIX_SYNCHRONIZED_IO _POSIX_VERSION
 #define _POSIX_THREAD_ATTR_STACKADDR _POSIX_VERSION /* Strictly, we're missing the deprecated pthread_attr_getstackaddr/pthread_attr_setstackaddr, but we do have pthread_attr_getstack/pthread_attr_setstack. */
 #define _POSIX_THREAD_ATTR_STACKSIZE _POSIX_VERSION /* pthread_attr_getstack/pthread_attr_getstacksize/pthread_attr_setstack/pthread_attr_setstacksize. */
@@ -82,7 +82,7 @@
 #define _POSIX_THREAD_ROBUST_PRIO_INHERIT __BIONIC_POSIX_FEATURE_MISSING
 #define _POSIX_THREAD_ROBUST_PRIO_PROTECT __BIONIC_POSIX_FEATURE_MISSING
 #define _POSIX_THREAD_SAFE_FUNCTIONS _POSIX_VERSION
-#define _POSIX_THREAD_SPORADIC_SERVER _POSIX_VERSION /* sched_setparam/sched_setscheduler. */
+#define _POSIX_THREAD_SPORADIC_SERVER __BIONIC_POSIX_FEATURE_MISSING /* No SCHED_SPORADIC. */
 #define _POSIX_THREADS _POSIX_VERSION /* Strictly, pthread_cancel/pthread_testcancel are missing. */
 #define _POSIX_TIMEOUTS __BIONIC_POSIX_FEATURE_SINCE(21) /* pthread_mutex_timedlock arrived late. */
 #define _POSIX_TIMERS _POSIX_VERSION /* clock_getres/clock_gettime/clock_settime/nanosleep/timer_create/timer_delete/timer_gettime/timer_getoverrun/timer_settime. */
@@ -94,6 +94,15 @@
 
 #define _POSIX_VDISABLE             '\0'
 
+#define _POSIX2_C_BIND              _POSIX_VERSION
+#define _POSIX2_C_DEV               __BIONIC_POSIX_FEATURE_MISSING
+#define _POSIX2_CHAR_TERM           _POSIX_VERSION
+#define _POSIX2_FORT_DEV            __BIONIC_POSIX_FEATURE_MISSING
+#define _POSIX2_FORT_RUN            __BIONIC_POSIX_FEATURE_MISSING
+#define _POSIX2_LOCALEDEF           __BIONIC_POSIX_FEATURE_MISSING
+#define _POSIX2_SW_DEV              __BIONIC_POSIX_FEATURE_MISSING
+#define _POSIX2_UPE                 __BIONIC_POSIX_FEATURE_MISSING
+
 #if defined(__LP64__)
 #define _POSIX_V7_ILP32_OFF32       -1
 #define _POSIX_V7_ILP32_OFFBIG      -1
@@ -106,16 +115,26 @@
 #define _POSIX_V7_LPBIG_OFFBIG      -1
 #endif
 
+#define _XOPEN_CRYPT                __BIONIC_POSIX_FEATURE_MISSING
+#define _XOPEN_ENH_I18N             1
+#define _XOPEN_LEGACY               __BIONIC_POSIX_FEATURE_MISSING
+#define _XOPEN_REALTIME             1
+#define _XOPEN_REALTIME_THREADS     1
+#define _XOPEN_SHM                  1
+#define _XOPEN_STREAMS              __BIONIC_POSIX_FEATURE_MISSING
+#define _XOPEN_UNIX                 1
+
 /* Minimum values for other maxima. These numbers are simply lower bounds mandated by POSIX. */
-/* Any constant values here other than -1 or 200809L are explicitly specified by POSIX.1-2008. */
+/* The constant values here are explicitly specified by POSIX, not implementation dependent. */
 #define _POSIX_AIO_LISTIO_MAX       2
 #define _POSIX_AIO_MAX              1
 #define _POSIX_ARG_MAX              4096
 #define _POSIX_CHILD_MAX            25
+#define _POSIX_CLOCKRES_MIN         20000000
 #define _POSIX_DELAYTIMER_MAX       32
 #define _POSIX_HOST_NAME_MAX        255
 #define _POSIX_LINK_MAX             8
-#define _POSIX_LOGIN_NAME_MAX       9  /* includes trailing NUL */
+#define _POSIX_LOGIN_NAME_MAX       9
 #define _POSIX_MAX_CANON            255
 #define _POSIX_MAX_INPUT            255
 #define _POSIX_MQ_OPEN_MAX          8
@@ -126,45 +145,36 @@
 #define _POSIX_PATH_MAX             256
 #define _POSIX_PIPE_BUF             512
 #define _POSIX_RE_DUP_MAX           255
+#define _POSIX_RTSIG_MAX            8
 #define _POSIX_SEM_NSEMS_MAX        256
 #define _POSIX_SEM_VALUE_MAX        32767
 #define _POSIX_SIGQUEUE_MAX         32
 #define _POSIX_SSIZE_MAX            32767
 #define _POSIX_STREAM_MAX           8
+#define _POSIX_SS_REPL_MAX          4
 #define _POSIX_SYMLINK_MAX          255
 #define _POSIX_SYMLOOP_MAX          8
 #define _POSIX_THREAD_DESTRUCTOR_ITERATIONS 4
 #define _POSIX_THREAD_KEYS_MAX      128
 #define _POSIX_THREAD_THREADS_MAX   64
 #define _POSIX_TIMER_MAX            32
+#define _POSIX_TRACE_EVENT_NAME_MAX 30
 #define _POSIX_TRACE_NAME_MAX       8
 #define _POSIX_TRACE_SYS_MAX        8
 #define _POSIX_TRACE_USER_EVENT_MAX 32
-#define _POSIX_TTY_NAME_MAX         9  /* includes trailing NUL */
+#define _POSIX_TTY_NAME_MAX         9
 #define _POSIX_TZNAME_MAX           6
 #define _POSIX2_BC_BASE_MAX         99
 #define _POSIX2_BC_DIM_MAX          2048
 #define _POSIX2_BC_SCALE_MAX        99
 #define _POSIX2_BC_STRING_MAX       1000
 #define _POSIX2_CHARCLASS_NAME_MAX  14
-#define _POSIX2_CHAR_TERM           -1  /* not implemented */
 #define _POSIX2_COLL_WEIGHTS_MAX    2
-#define _POSIX2_C_BIND              _POSIX_VERSION
-#define _POSIX2_C_DEV               -1  /* c dev utilities not implemented */
 #define _POSIX2_EXPR_NEST_MAX       32
 #define _POSIX2_LINE_MAX            2048
-#define _POSIX2_LOCALEDEF           -1  /* localedef utilitiy not implemented */
-#define _POSIX2_RE_DUP_MAX          _POSIX_RE_DUP_MAX
-#define _POSIX2_SW_DEV              -1  /* software dev utilities not implemented */
-#define _POSIX2_UPE                 -1  /* user portability utilities not implemented */
-
-#define _XOPEN_ENH_I18N             -1  /* we don't support internationalization in the C library */
-#define _XOPEN_CRYPT                -1  /* don't support X/Open Encryption */
+#define _POSIX2_RE_DUP_MAX          255
 #define _XOPEN_IOV_MAX              16
-#define _XOPEN_LEGACY               -1  /* not support all */
-#define _XOPEN_REALTIME             -1 /* we don't support all these functions */
-#define _XOPEN_REALTIME_THREADS     -1  /* same here */
-#define _XOPEN_SHM                  -1
-#define _XOPEN_UNIX                 1
+#define _XOPEN_NAME_MAX             255
+#define _XOPEN_PATH_MAX             1024
 
 #endif