diff --git a/libc/include/sys/limits.h b/libc/include/sys/limits.h
index edb8c47..be79cf3 100644
--- a/libc/include/sys/limits.h
+++ b/libc/include/sys/limits.h
@@ -115,31 +115,13 @@
 
 /* Bionic-specific definitions */
 
-#define  _POSIX_VERSION             200112L   /* Posix C language bindings version */
+#define  _POSIX_VERSION             200809L   /* Posix C language bindings version */
 #define  _POSIX2_VERSION            -1        /* we don't support Posix command-line tools */
-#define  _POSIX2_C_VERSION          _POSIX_VERSION
-#define  _XOPEN_VERSION             500       /* by Posix definition */
-#define  _XOPEN_XCU_VERSION         -1        /* we don't support command-line utilities */
+#define  _XOPEN_VERSION             700       /* by Posix definition */
 
-/* tell what we implement legacy stuff when appropriate */
-#if _POSIX_VERSION > 0
-#define  _XOPEN_XPG2                1
-#define  _XOPEN_XPG3                1
-#define  _XOPEN_XPG4                1
-#define  _XOPEN_UNIX                1
-#endif
 
-#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  _XOPEN_LEGACY            -1  /* don't claim we support these, we have some of them but not all */
-#define  _XOPEN_REALTIME          -1 /* we don't support all these functions */
-#define  _XOPEN_REALTIME_THREADS  -1  /* same here */
-
-#define _POSIX_THREAD_DESTRUCTOR_ITERATIONS 4 /* the minimum mandated by POSIX */
-#define PTHREAD_DESTRUCTOR_ITERATIONS _POSIX_THREAD_DESTRUCTOR_ITERATIONS
-#define _POSIX_THREAD_KEYS_MAX 128            /* the minimum mandated by POSIX */
-#define PTHREAD_KEYS_MAX _POSIX_THREAD_KEYS_MAX
-#define _POSIX_THREAD_THREADS_MAX 64          /* the minimum mandated by POSIX */
-#define PTHREAD_THREADS_MAX                   /* bionic has no specific limit */
+#define PTHREAD_DESTRUCTOR_ITERATIONS 4     // >= _POSIX_THREAD_DESTRUCTOR_ITERATIONS
+#define PTHREAD_KEYS_MAX              128   // >= _POSIX_THREAD_KEYS_MAX
+#define PTHREAD_THREADS_MAX           2048  // bionic has no specific limit
 
 #endif
diff --git a/libc/include/sys/sysconf.h b/libc/include/sys/sysconf.h
index 3d058d7..8aa506e 100644
--- a/libc/include/sys/sysconf.h
+++ b/libc/include/sys/sysconf.h
@@ -50,7 +50,7 @@
 #define _SC_PASS_MAX            0x000c
 #define _SC_2_C_BIND            0x000d
 #define _SC_2_C_DEV             0x000e
-#define _SC_2_C_VERSION         0x000f
+#define _SC_2_C_VERSION         0x000f  /* Obsolescent in POSIX.1-2008, TODO: remove it. */
 #define _SC_2_CHAR_TERM         0x0010
 #define _SC_2_FORT_DEV          0x0011
 #define _SC_2_FORT_RUN          0x0012
@@ -68,7 +68,7 @@
 #define _SC_XOPEN_ENH_I18N      0x001e
 #define _SC_XOPEN_SHM           0x001f
 #define _SC_XOPEN_VERSION       0x0020
-#define _SC_XOPEN_XCU_VERSION   0x0021
+#define _SC_XOPEN_XCU_VERSION   0x0021  /* Obsolescent in POSIX.1-2008, TODO: remove it. */
 #define _SC_XOPEN_REALTIME      0x0022
 #define _SC_XOPEN_REALTIME_THREADS  0x0023
 #define _SC_XOPEN_LEGACY        0x0024
@@ -77,10 +77,10 @@
 #define _SC_PAGESIZE            0x0027
 #define _SC_PAGE_SIZE           0x0028
 #define _SC_XOPEN_UNIX          0x0029
-#define _SC_XBS5_ILP32_OFF32    0x002a
-#define _SC_XBS5_ILP32_OFFBIG   0x002b
-#define _SC_XBS5_LP64_OFF64     0x002c
-#define _SC_XBS5_LPBIG_OFFBIG   0x002d
+#define _SC_XBS5_ILP32_OFF32    0x002a  /* Obsolescent in POSIX.1-2008, TODO: remove it. */
+#define _SC_XBS5_ILP32_OFFBIG   0x002b  /* Obsolescent in POSIX.1-2008, TODO: remove it. */
+#define _SC_XBS5_LP64_OFF64     0x002c  /* Obsolescent in POSIX.1-2008, TODO: remove it. */
+#define _SC_XBS5_LPBIG_OFFBIG   0x002d  /* Obsolescent in POSIX.1-2008, TODO: remove it. */
 #define _SC_AIO_LISTIO_MAX      0x002e
 #define _SC_AIO_MAX             0x002f
 #define _SC_AIO_PRIO_DELTA_MAX  0x0030
@@ -129,6 +129,49 @@
 #define _SC_AVPHYS_PAGES                0x0063
 #define _SC_MONOTONIC_CLOCK             0x0064
 
+#define _SC_2_PBS               0x0065
+#define _SC_2_PBS_ACCOUNTING    0x0066
+#define _SC_2_PBS_CHECKPOINT    0x0067
+#define _SC_2_PBS_LOCATE        0x0068
+#define _SC_2_PBS_MESSAGE       0x0069
+#define _SC_2_PBS_TRACK         0x006a
+#define _SC_ADVISORY_INFO       0x006b
+#define _SC_BARRIERS            0x006c
+#define _SC_CLOCK_SELECTION     0x006d
+#define _SC_CPUTIME             0x006e
+#define _SC_HOST_NAME_MAX       0x006f
+#define _SC_IPV6                0x0070
+#define _SC_RAW_SOCKETS         0x0071
+#define _SC_READER_WRITER_LOCKS 0x0072
+#define _SC_REGEXP              0x0073
+#define _SC_SHELL               0x0074
+#define _SC_SPAWN               0x0075
+#define _SC_SPIN_LOCKS          0x0076
+#define _SC_SPORADIC_SERVER     0x0077
+#define _SC_SS_REPL_MAX         0x0078
+#define _SC_SYMLOOP_MAX         0x0079
+#define _SC_THREAD_CPUTIME      0x007a
+#define _SC_THREAD_PROCESS_SHARED       0x007b
+#define _SC_THREAD_ROBUST_PRIO_INHERIT  0x007c
+#define _SC_THREAD_ROBUST_PRIO_PROTECT  0x007d
+#define _SC_THREAD_SPORADIC_SERVER      0x007e
+#define _SC_TIMEOUTS            0x007f
+#define _SC_TRACE               0x0080
+#define _SC_TRACE_EVENT_FILTER  0x0081
+#define _SC_TRACE_EVENT_NAME_MAX  0x0082
+#define _SC_TRACE_INHERIT       0x0083
+#define _SC_TRACE_LOG           0x0084
+#define _SC_TRACE_NAME_MAX      0x0085
+#define _SC_TRACE_SYS_MAX       0x0086
+#define _SC_TRACE_USER_EVENT_MAX  0x0087
+#define _SC_TYPED_MEMORY_OBJECTS  0x0088
+#define _SC_V7_ILP32_OFF32      0x0089
+#define _SC_V7_ILP32_OFFBIG     0x008a
+#define _SC_V7_LP64_OFF64       0x008b
+#define _SC_V7_LPBIG_OFFBIG     0x008c
+#define _SC_XOPEN_STREAMS       0x008d
+#define _SC_XOPEN_UUCP          0x008e
+
 long sysconf(int);
 
 __END_DECLS