diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index 98695eb..1f08628 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -116,10 +116,10 @@
 int pthread_attr_setstacksize(pthread_attr_t* _Nonnull __addr, size_t __size);
 
 int pthread_condattr_destroy(pthread_condattr_t* _Nonnull __attr);
-int pthread_condattr_getclock(const pthread_condattr_t* _Nonnull __attr, clockid_t* _Nonnull __clock) __INTRODUCED_IN(21);
+int pthread_condattr_getclock(const pthread_condattr_t* _Nonnull __attr, clockid_t* _Nonnull __clock);
 int pthread_condattr_getpshared(const pthread_condattr_t* _Nonnull __attr, int* _Nonnull __shared);
 int pthread_condattr_init(pthread_condattr_t* _Nonnull __attr);
-int pthread_condattr_setclock(pthread_condattr_t* _Nonnull __attr, clockid_t __clock) __INTRODUCED_IN(21);
+int pthread_condattr_setclock(pthread_condattr_t* _Nonnull __attr, clockid_t __clock);
 int pthread_condattr_setpshared(pthread_condattr_t* _Nonnull __attr, int __shared);
 
 int pthread_cond_broadcast(pthread_cond_t* _Nonnull __cond);
@@ -169,7 +169,7 @@
 
 void* _Nullable pthread_getspecific(pthread_key_t __key);
 
-pid_t pthread_gettid_np(pthread_t __pthread) __INTRODUCED_IN(21);
+pid_t pthread_gettid_np(pthread_t __pthread);
 
 int pthread_join(pthread_t __pthread, void* _Nullable * _Nullable __return_value_ptr);
 
@@ -190,8 +190,7 @@
 int pthread_mutex_destroy(pthread_mutex_t* _Nonnull __mutex);
 int pthread_mutex_init(pthread_mutex_t* _Nonnull __mutex, const pthread_mutexattr_t* _Nullable __attr);
 int pthread_mutex_lock(pthread_mutex_t* _Nonnull __mutex);
-int pthread_mutex_timedlock(pthread_mutex_t* _Nonnull __mutex, const struct timespec* _Nullable __timeout)
-  __INTRODUCED_IN(21);
+int pthread_mutex_timedlock(pthread_mutex_t* _Nonnull __mutex, const struct timespec* _Nullable __timeout);
 
 /*
  * POSIX historically only supported using pthread_mutex_timedlock() with CLOCK_REALTIME, however