diff --git a/include/pthread.h b/include/pthread.h
index be555fed75..a75cd9e901 100644
--- a/include/pthread.h
+++ b/include/pthread.h
@@ -343,6 +343,7 @@ struct pthread_rwlock_s
     pthread_cond_t  cv;
     unsigned int num_readers;
     unsigned int num_writers;
+    bool write_in_progress;
 };
 
 typedef struct pthread_rwlock_s pthread_rwlock_t;
diff --git a/libc/pthread/pthread_rwlock.c b/libc/pthread/pthread_rwlock.c
index 3f902089b0..b40b655b26 100644
--- a/libc/pthread/pthread_rwlock.c
+++ b/libc/pthread/pthread_rwlock.c
@@ -60,8 +60,9 @@ int pthread_rwlock_init(FAR pthread_rwlock_t *lock,
       return -ENOSYS;
     }
 
-  lock->num_readers = 0;
-  lock->num_writers = 0;
+  lock->num_readers       = 0;
+  lock->num_writers       = 0;
+  lock->write_in_progress = false;
 
   err = pthread_cond_init(&lock->cv, NULL);
   if (err != 0)
@@ -111,9 +112,9 @@ int pthread_rwlock_unlock(FAR pthread_rwlock_t *rw_lock)
           err = pthread_cond_broadcast(&rw_lock->cv);
         }
     }
-  else if (rw_lock->num_writers > 0)
+  else if (rw_lock->write_in_progress)
     {
-      rw_lock->num_writers--;
+      rw_lock->write_in_progress = false;
 
       err = pthread_cond_broadcast(&rw_lock->cv);
     }
diff --git a/libc/pthread/pthread_rwlock_rdlock.c b/libc/pthread/pthread_rwlock_rdlock.c
index 6270d2bbe4..9fd461a758 100644
--- a/libc/pthread/pthread_rwlock_rdlock.c
+++ b/libc/pthread/pthread_rwlock_rdlock.c
@@ -54,7 +54,7 @@ static int tryrdlock(FAR pthread_rwlock_t *rw_lock)
 {
   int err;
 
-  if (rw_lock->num_writers > 0)
+  if (rw_lock->num_writers > 0 || rw_lock->write_in_progress)
     {
       err = EBUSY;
     }
diff --git a/libc/pthread/pthread_rwlock_wrlock.c b/libc/pthread/pthread_rwlock_wrlock.c
index dc2d155021..ecda4cb25b 100644
--- a/libc/pthread/pthread_rwlock_wrlock.c
+++ b/libc/pthread/pthread_rwlock_wrlock.c
@@ -75,13 +75,13 @@ int pthread_rwlock_trywrlock(FAR pthread_rwlock_t *rw_lock)
       return err;
     }
 
-  if (rw_lock->num_readers > 0 || rw_lock->num_writers > 0)
+  if (rw_lock->num_readers > 0 || rw_lock->write_in_progress)
     {
       err = EBUSY;
     }
   else
     {
-      rw_lock->num_writers++;
+      rw_lock->write_in_progress = true;
     }
 
   pthread_mutex_unlock(&rw_lock->lock);
@@ -92,20 +92,21 @@ int pthread_rwlock_timedwrlock(FAR pthread_rwlock_t *rw_lock,
                                FAR const struct timespec *ts)
 {
   int err = pthread_mutex_lock(&rw_lock->lock);
-  int num_writers_current;
 
   if (err != 0)
     {
       return err;
     }
 
-  num_writers_current = rw_lock->num_writers++;
-  if (num_writers_current == 0)
+  if (rw_lock->num_writers == UINT_MAX)
     {
+      err = EAGAIN;
       goto exit_with_mutex;
     }
 
-  while (rw_lock->num_writers != num_writers_current)
+  rw_lock->num_writers++;
+
+  while (rw_lock->write_in_progress || rw_lock->num_readers > 0)
     {
       if (ts != NULL)
         {
@@ -122,6 +123,20 @@ int pthread_rwlock_timedwrlock(FAR pthread_rwlock_t *rw_lock,
         }
     }
 
+  if (err == 0)
+    {
+      rw_lock->write_in_progress = true;
+    }
+
+  else
+    {
+      /* In case of error, notify any blocked readers. */
+
+      (void) pthread_cond_broadcast(&rw_lock->cv);
+    }
+
+  rw_lock->num_writers--;
+
 exit_with_mutex:
   pthread_mutex_unlock(&rw_lock->lock);
   return err;