diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index e7df34a9..9f6b98e6 100644
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -79,7 +79,7 @@ _Noreturn void __pthread_exit(void *result)
 		int priv = (m->_m_type & 128) ^ 128;
 		self->robust_list.pending = rp;
 		self->robust_list.head = *rp;
-		int cont = a_swap(&m->_m_lock, self->tid|0x40000000);
+		int cont = a_swap(&m->_m_lock, 0x40000000);
 		self->robust_list.pending = 0;
 		if (cont < 0 || waiters)
 			__wake(&m->_m_lock, 1, priv);
diff --git a/src/thread/pthread_mutex_trylock.c b/src/thread/pthread_mutex_trylock.c
index 0df3ce29..54876a61 100644
--- a/src/thread/pthread_mutex_trylock.c
+++ b/src/thread/pthread_mutex_trylock.c
@@ -14,7 +14,7 @@ int __pthread_mutex_trylock_owner(pthread_mutex_t *m)
 		m->_m_count++;
 		return 0;
 	}
-	if (own == 0x40000000) return ENOTRECOVERABLE;
+	if (own == 0x7fffffff) return ENOTRECOVERABLE;
 
 	if (m->_m_type & 128) {
 		if (!self->robust_list.off) {
diff --git a/src/thread/pthread_mutex_unlock.c b/src/thread/pthread_mutex_unlock.c
index 02da92a9..7dd00d27 100644
--- a/src/thread/pthread_mutex_unlock.c
+++ b/src/thread/pthread_mutex_unlock.c
@@ -24,7 +24,7 @@ int __pthread_mutex_unlock(pthread_mutex_t *m)
 		if (next != &self->robust_list.head) *(volatile void *volatile *)
 			((char *)next - sizeof(void *)) = prev;
 	}
-	cont = a_swap(&m->_m_lock, (type & 8) ? 0x40000000 : 0);
+	cont = a_swap(&m->_m_lock, (type & 8) ? 0x7fffffff : 0);
 	if (type != PTHREAD_MUTEX_NORMAL && !priv) {
 		self->robust_list.pending = 0;
 		__vm_unlock();