diff --git a/libc/bionic/pthread_cond.cpp b/libc/bionic/pthread_cond.cpp
index 4a69da5..adbce07 100644
--- a/libc/bionic/pthread_cond.cpp
+++ b/libc/bionic/pthread_cond.cpp
@@ -111,8 +111,8 @@
     return COND_IS_SHARED(atomic_load_explicit(&state, memory_order_relaxed));
   }
 
-  int get_clock() {
-    return COND_GET_CLOCK(atomic_load_explicit(&state, memory_order_relaxed));
+  bool use_realtime_clock() {
+    return COND_GET_CLOCK(atomic_load_explicit(&state, memory_order_relaxed)) == CLOCK_REALTIME;
   }
 
 #if defined(__LP64__)
@@ -170,12 +170,17 @@
   return 0;
 }
 
-static int __pthread_cond_timedwait_relative(pthread_cond_internal_t* cond, pthread_mutex_t* mutex,
-                                             const timespec* rel_timeout_or_null) {
-  unsigned int old_state = atomic_load_explicit(&cond->state, memory_order_relaxed);
+static int __pthread_cond_timedwait(pthread_cond_internal_t* cond, pthread_mutex_t* mutex,
+                                    bool use_realtime_clock, const timespec* abs_timeout_or_null) {
+  int result = check_timespec(abs_timeout_or_null);
+  if (result != 0) {
+    return result;
+  }
 
+  unsigned int old_state = atomic_load_explicit(&cond->state, memory_order_relaxed);
   pthread_mutex_unlock(mutex);
-  int status = __futex_wait_ex(&cond->state, cond->process_shared(), old_state, rel_timeout_or_null);
+  int status = __futex_wait_ex(&cond->state, cond->process_shared(), old_state,
+                               use_realtime_clock, abs_timeout_or_null);
   pthread_mutex_lock(mutex);
 
   if (status == -ETIMEDOUT) {
@@ -184,21 +189,6 @@
   return 0;
 }
 
-static int __pthread_cond_timedwait(pthread_cond_internal_t* cond, pthread_mutex_t* mutex,
-                                    const timespec* abs_timeout_or_null, clockid_t clock) {
-  timespec ts;
-  timespec* rel_timeout = NULL;
-
-  if (abs_timeout_or_null != NULL) {
-    rel_timeout = &ts;
-    if (!timespec_from_absolute_timespec(*rel_timeout, *abs_timeout_or_null, clock)) {
-      return ETIMEDOUT;
-    }
-  }
-
-  return __pthread_cond_timedwait_relative(cond, mutex, rel_timeout);
-}
-
 int pthread_cond_broadcast(pthread_cond_t* cond_interface) {
   return __pthread_cond_pulse(__get_internal_cond(cond_interface), INT_MAX);
 }
@@ -209,14 +199,14 @@
 
 int pthread_cond_wait(pthread_cond_t* cond_interface, pthread_mutex_t* mutex) {
   pthread_cond_internal_t* cond = __get_internal_cond(cond_interface);
-  return __pthread_cond_timedwait(cond, mutex, NULL, cond->get_clock());
+  return __pthread_cond_timedwait(cond, mutex, false, nullptr);
 }
 
 int pthread_cond_timedwait(pthread_cond_t *cond_interface, pthread_mutex_t * mutex,
                            const timespec *abstime) {
 
   pthread_cond_internal_t* cond = __get_internal_cond(cond_interface);
-  return __pthread_cond_timedwait(cond, mutex, abstime, cond->get_clock());
+  return __pthread_cond_timedwait(cond, mutex, cond->use_realtime_clock(), abstime);
 }
 
 #if !defined(__LP64__)
@@ -225,8 +215,7 @@
                                                 pthread_mutex_t* mutex,
                                                 const timespec* abs_timeout) {
 
-  return __pthread_cond_timedwait(__get_internal_cond(cond_interface), mutex, abs_timeout,
-                                  CLOCK_MONOTONIC);
+  return __pthread_cond_timedwait(__get_internal_cond(cond_interface), mutex, false, abs_timeout);
 }
 
 extern "C" int pthread_cond_timedwait_monotonic_np(pthread_cond_t* cond_interface,
@@ -238,8 +227,13 @@
 extern "C" int pthread_cond_timedwait_relative_np(pthread_cond_t* cond_interface,
                                                   pthread_mutex_t* mutex,
                                                   const timespec* rel_timeout) {
-
-  return __pthread_cond_timedwait_relative(__get_internal_cond(cond_interface), mutex, rel_timeout);
+  timespec ts;
+  timespec* abs_timeout = nullptr;
+  if (rel_timeout != nullptr) {
+    absolute_timespec_from_timespec(ts, *rel_timeout, CLOCK_REALTIME);
+    abs_timeout = &ts;
+  }
+  return __pthread_cond_timedwait(__get_internal_cond(cond_interface), mutex, true, abs_timeout);
 }
 
 extern "C" int pthread_cond_timeout_np(pthread_cond_t* cond_interface,