diff --git a/libc/include/sys/_system_properties.h b/libc/include/sys/_system_properties.h
index 186d390..f8dbd33 100644
--- a/libc/include/sys/_system_properties.h
+++ b/libc/include/sys/_system_properties.h
@@ -30,7 +30,6 @@
 #define _INCLUDE_SYS__SYSTEM_PROPERTIES_H
 
 #include <sys/cdefs.h>
-#include <stdbool.h>
 #include <stdint.h>
 
 #ifndef _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
@@ -122,25 +121,6 @@
 */
 uint32_t __system_property_serial(const prop_info* pi);
 
-/*
- * Waits for the specific system property identified by `pi` to be updated
- * past `old_serial`. Waits no longer than `relative_timeout`, or forever
- * if `relaive_timeout` is null.
- *
- * If `pi` is null, waits for the global serial number instead.
- *
- * If you don't know the current serial, use 0.
- *
- * Returns true and updates `*new_serial_ptr` on success, or false if the call
- * timed out.
- */
-struct timespec;
-bool __system_property_wait(const prop_info* pi,
-                            uint32_t old_serial,
-                            uint32_t* new_serial_ptr,
-                            const struct timespec* relative_timeout)
-    __INTRODUCED_IN_FUTURE;
-
 /* Initialize the system properties area in read only mode.
  * Should be done by all processes that need to read system
  * properties.
diff --git a/libc/include/sys/system_properties.h b/libc/include/sys/system_properties.h
index fb90251..b55566e 100644
--- a/libc/include/sys/system_properties.h
+++ b/libc/include/sys/system_properties.h
@@ -30,6 +30,7 @@
 #define _INCLUDE_SYS_SYSTEM_PROPERTIES_H
 
 #include <sys/cdefs.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -68,6 +69,25 @@
 int __system_property_foreach(void (*propfn)(const prop_info* pi, void* cookie), void* cookie)
   __INTRODUCED_IN(19);
 
+/*
+ * Waits for the specific system property identified by `pi` to be updated
+ * past `old_serial`. Waits no longer than `relative_timeout`, or forever
+ * if `relaive_timeout` is null.
+ *
+ * If `pi` is null, waits for the global serial number instead.
+ *
+ * If you don't know the current serial, use 0.
+ *
+ * Returns true and updates `*new_serial_ptr` on success, or false if the call
+ * timed out.
+ */
+struct timespec;
+bool __system_property_wait(const prop_info* pi,
+                            uint32_t old_serial,
+                            uint32_t* new_serial_ptr,
+                            const struct timespec* relative_timeout)
+    __INTRODUCED_IN_FUTURE;
+
 /* Deprecated. In Android O and above, there's no limit on property name length. */
 #define PROP_NAME_MAX   32
 /* Deprecated. Use __system_property_read_callback instead. */
diff --git a/libc/libc.arm.map b/libc/libc.arm.map
index ebe249f..798b9c3 100644
--- a/libc/libc.arm.map
+++ b/libc/libc.arm.map
@@ -185,18 +185,11 @@
     __sym_ntop;
     __sym_ntos;
     __sym_ston;
-    __system_properties_init;
-    __system_property_area__; # var
-    __system_property_area_init; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_area_serial; # introduced=23
     __system_property_find;
     __system_property_foreach; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_get;
     __system_property_read;
-    __system_property_serial; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_set; # introduced-arm=12 introduced-arm64=21 introduced-mips=12 introduced-mips64=21 introduced-x86=12 introduced-x86_64=21
-    __system_property_set_filename; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_wait_any; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __timer_create; # arm x86 mips
     __timer_delete; # arm x86 mips
     __timer_getoverrun; # arm x86 mips
@@ -1538,11 +1531,18 @@
 LIBC_DEPRECATED {
   global:
     __system_property_find_nth;
+    __system_property_wait_any;
 };
 
 LIBC_PLATFORM {
   global:
+    __system_properties_init;
+    __system_property_area__; # var
     __system_property_add;
+    __system_property_area_init;
+    __system_property_area_serial;
+    __system_property_serial;
+    __system_property_set_filename;
     __system_property_update;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;
diff --git a/libc/libc.arm64.map b/libc/libc.arm64.map
index 74d0171..c686bb9 100644
--- a/libc/libc.arm64.map
+++ b/libc/libc.arm64.map
@@ -130,18 +130,11 @@
     __sym_ntop;
     __sym_ntos;
     __sym_ston;
-    __system_properties_init;
-    __system_property_area__; # var
-    __system_property_area_init; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_area_serial; # introduced=23
     __system_property_find;
     __system_property_foreach; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_get;
     __system_property_read;
-    __system_property_serial; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_set; # introduced-arm=12 introduced-arm64=21 introduced-mips=12 introduced-mips64=21 introduced-x86=12 introduced-x86_64=21
-    __system_property_set_filename; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_wait_any; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __umask_chk; # introduced-arm=18 introduced-arm64=21 introduced-mips=18 introduced-mips64=21 introduced-x86=18 introduced-x86_64=21
     __vsnprintf_chk; # introduced-arm=17 introduced-arm64=21 introduced-mips=17 introduced-mips64=21 introduced-x86=17 introduced-x86_64=21
     __vsprintf_chk; # introduced-arm=17 introduced-arm64=21 introduced-mips=17 introduced-mips64=21 introduced-x86=17 introduced-x86_64=21
@@ -1255,11 +1248,18 @@
 LIBC_DEPRECATED {
   global:
     __system_property_find_nth;
+    __system_property_wait_any;
 };
 
 LIBC_PLATFORM {
   global:
+    __system_properties_init;
+    __system_property_area__; # var
     __system_property_add;
+    __system_property_area_init;
+    __system_property_area_serial;
+    __system_property_serial;
+    __system_property_set_filename;
     __system_property_update;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 6afea32..1217bd5 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -186,18 +186,11 @@
     __sym_ntop;
     __sym_ntos;
     __sym_ston;
-    __system_properties_init;
-    __system_property_area__; # var
-    __system_property_area_init; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_area_serial; # introduced=23
     __system_property_find;
     __system_property_foreach; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_get;
     __system_property_read;
-    __system_property_serial; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_set; # introduced-arm=12 introduced-arm64=21 introduced-mips=12 introduced-mips64=21 introduced-x86=12 introduced-x86_64=21
-    __system_property_set_filename; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_wait_any; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __timer_create; # arm x86 mips
     __timer_delete; # arm x86 mips
     __timer_getoverrun; # arm x86 mips
@@ -1564,11 +1557,18 @@
 LIBC_DEPRECATED {
   global:
     __system_property_find_nth;
+    __system_property_wait_any;
 };
 
 LIBC_PLATFORM {
   global:
+    __system_properties_init;
+    __system_property_area__; # var
     __system_property_add;
+    __system_property_area_init;
+    __system_property_area_serial;
+    __system_property_serial;
+    __system_property_set_filename;
     __system_property_update;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;
diff --git a/libc/libc.mips.map b/libc/libc.mips.map
index d67c0f3..79fbc1a 100644
--- a/libc/libc.mips.map
+++ b/libc/libc.mips.map
@@ -182,18 +182,11 @@
     __sym_ntop;
     __sym_ntos;
     __sym_ston;
-    __system_properties_init;
-    __system_property_area__; # var
-    __system_property_area_init; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_area_serial; # introduced=23
     __system_property_find;
     __system_property_foreach; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_get;
     __system_property_read;
-    __system_property_serial; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_set; # introduced-arm=12 introduced-arm64=21 introduced-mips=12 introduced-mips64=21 introduced-x86=12 introduced-x86_64=21
-    __system_property_set_filename; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_wait_any; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __timer_create; # arm x86 mips
     __timer_delete; # arm x86 mips
     __timer_getoverrun; # arm x86 mips
@@ -1379,11 +1372,18 @@
 LIBC_DEPRECATED {
   global:
     __system_property_find_nth;
+    __system_property_wait_any;
 };
 
 LIBC_PLATFORM {
   global:
+    __system_properties_init;
+    __system_property_area__; # var
     __system_property_add;
+    __system_property_area_init;
+    __system_property_area_serial;
+    __system_property_serial;
+    __system_property_set_filename;
     __system_property_update;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;
diff --git a/libc/libc.mips64.map b/libc/libc.mips64.map
index 74d0171..c686bb9 100644
--- a/libc/libc.mips64.map
+++ b/libc/libc.mips64.map
@@ -130,18 +130,11 @@
     __sym_ntop;
     __sym_ntos;
     __sym_ston;
-    __system_properties_init;
-    __system_property_area__; # var
-    __system_property_area_init; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_area_serial; # introduced=23
     __system_property_find;
     __system_property_foreach; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_get;
     __system_property_read;
-    __system_property_serial; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_set; # introduced-arm=12 introduced-arm64=21 introduced-mips=12 introduced-mips64=21 introduced-x86=12 introduced-x86_64=21
-    __system_property_set_filename; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_wait_any; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __umask_chk; # introduced-arm=18 introduced-arm64=21 introduced-mips=18 introduced-mips64=21 introduced-x86=18 introduced-x86_64=21
     __vsnprintf_chk; # introduced-arm=17 introduced-arm64=21 introduced-mips=17 introduced-mips64=21 introduced-x86=17 introduced-x86_64=21
     __vsprintf_chk; # introduced-arm=17 introduced-arm64=21 introduced-mips=17 introduced-mips64=21 introduced-x86=17 introduced-x86_64=21
@@ -1255,11 +1248,18 @@
 LIBC_DEPRECATED {
   global:
     __system_property_find_nth;
+    __system_property_wait_any;
 };
 
 LIBC_PLATFORM {
   global:
+    __system_properties_init;
+    __system_property_area__; # var
     __system_property_add;
+    __system_property_area_init;
+    __system_property_area_serial;
+    __system_property_serial;
+    __system_property_set_filename;
     __system_property_update;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;
diff --git a/libc/libc.x86.map b/libc/libc.x86.map
index bbba189..a968693 100644
--- a/libc/libc.x86.map
+++ b/libc/libc.x86.map
@@ -182,18 +182,11 @@
     __sym_ntop;
     __sym_ntos;
     __sym_ston;
-    __system_properties_init;
-    __system_property_area__; # var
-    __system_property_area_init; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_area_serial; # introduced=23
     __system_property_find;
     __system_property_foreach; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_get;
     __system_property_read;
-    __system_property_serial; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_set; # introduced-arm=12 introduced-arm64=21 introduced-mips=12 introduced-mips64=21 introduced-x86=12 introduced-x86_64=21
-    __system_property_set_filename; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_wait_any; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __timer_create; # arm x86 mips
     __timer_delete; # arm x86 mips
     __timer_getoverrun; # arm x86 mips
@@ -1378,11 +1371,18 @@
 LIBC_DEPRECATED {
   global:
     __system_property_find_nth;
+    __system_property_wait_any;
 };
 
 LIBC_PLATFORM {
   global:
+    __system_properties_init;
+    __system_property_area__; # var
     __system_property_add;
+    __system_property_area_init;
+    __system_property_area_serial;
+    __system_property_serial;
+    __system_property_set_filename;
     __system_property_update;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;
diff --git a/libc/libc.x86_64.map b/libc/libc.x86_64.map
index 74d0171..c686bb9 100644
--- a/libc/libc.x86_64.map
+++ b/libc/libc.x86_64.map
@@ -130,18 +130,11 @@
     __sym_ntop;
     __sym_ntos;
     __sym_ston;
-    __system_properties_init;
-    __system_property_area__; # var
-    __system_property_area_init; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_area_serial; # introduced=23
     __system_property_find;
     __system_property_foreach; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_get;
     __system_property_read;
-    __system_property_serial; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __system_property_set; # introduced-arm=12 introduced-arm64=21 introduced-mips=12 introduced-mips64=21 introduced-x86=12 introduced-x86_64=21
-    __system_property_set_filename; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
-    __system_property_wait_any; # introduced-arm=19 introduced-arm64=21 introduced-mips=19 introduced-mips64=21 introduced-x86=19 introduced-x86_64=21
     __umask_chk; # introduced-arm=18 introduced-arm64=21 introduced-mips=18 introduced-mips64=21 introduced-x86=18 introduced-x86_64=21
     __vsnprintf_chk; # introduced-arm=17 introduced-arm64=21 introduced-mips=17 introduced-mips64=21 introduced-x86=17 introduced-x86_64=21
     __vsprintf_chk; # introduced-arm=17 introduced-arm64=21 introduced-mips=17 introduced-mips64=21 introduced-x86=17 introduced-x86_64=21
@@ -1255,11 +1248,18 @@
 LIBC_DEPRECATED {
   global:
     __system_property_find_nth;
+    __system_property_wait_any;
 };
 
 LIBC_PLATFORM {
   global:
+    __system_properties_init;
+    __system_property_area__; # var
     __system_property_add;
+    __system_property_area_init;
+    __system_property_area_serial;
+    __system_property_serial;
+    __system_property_set_filename;
     __system_property_update;
     android_net_res_stats_get_info_for_net;
     android_net_res_stats_aggregate;