diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index cdf1b8c..f3b7068 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -170,8 +170,6 @@
 
 int pthread_getcpuclockid(pthread_t __pthread, clockid_t* _Nonnull __clock);
 
-void* _Nullable pthread_getspecific(pthread_key_t __key);
-
 pid_t pthread_gettid_np(pthread_t __pthread);
 
 int pthread_join(pthread_t __pthread, void* _Nullable * _Nullable __return_value_ptr);
@@ -189,6 +187,9 @@
  * different language, you should consider similar implementation choices and
  * avoid a direct one-to-one mapping from thread locals to pthread keys.
  *
+ * On Android, the destructor function is called even for null values,
+ * even though POSIX specifies that it is only called for non-null values.
+ *
  * Returns 0 on success and returns an error number on failure.
  */
 int pthread_key_create(pthread_key_t* _Nonnull __key_ptr, void (* _Nullable __key_destructor)(void* _Nullable));
@@ -197,10 +198,28 @@
  * [pthread_key_delete(3)](https://man7.org/linux/man-pages/man3/pthread_key_delete.3p.html)
  * deletes a key for thread-specific data.
  *
+ * Note that pthread_key_delete() does _not_ run destructor functions:
+ * the caller must take care of any necessary cleanup of thread-specific data themselves.
+ * This function only deletes the key itself.
+ *
  * Returns 0 on success and returns an error number on failure.
  */
 int pthread_key_delete(pthread_key_t __key);
 
+/**
+ * [pthread_getspecific(3)](https://man7.org/linux/man-pages/man3/pthread_getspecific.3p.html)
+ * returns the calling thread's thread-specific value for the given key.
+ */
+void* _Nullable pthread_getspecific(pthread_key_t __key);
+
+/**
+ * [pthread_setspecific(3)](https://man7.org/linux/man-pages/man3/pthread_setspecific.3p.html)
+ * sets the calling thread's thread-specific value for the given key.
+ *
+ * Returns 0 on success and returns an error number on failure.
+ */
+int pthread_setspecific(pthread_key_t __key, const void* _Nullable __value);
+
 int pthread_mutexattr_destroy(pthread_mutexattr_t* _Nonnull __attr);
 int pthread_mutexattr_getpshared(const pthread_mutexattr_t* _Nonnull __attr, int* _Nonnull __shared);
 int pthread_mutexattr_gettype(const pthread_mutexattr_t* _Nonnull __attr, int* _Nonnull __type);
@@ -406,9 +425,6 @@
 int pthread_setschedprio(pthread_t __pthread, int __priority) __INTRODUCED_IN(28);
 #endif /* __BIONIC_AVAILABILITY_GUARD(28) */
 
-
-int pthread_setspecific(pthread_key_t __key, const void* _Nullable __value);
-
 typedef void (* _Nullable __pthread_cleanup_func_t)(void* _Nullable);
 
 typedef struct __pthread_cleanup_t {