diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index bec8f6b..092aaae 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -419,7 +419,10 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts,
 	all_time -= lockstat_nsecs(&m->lock_object);
 #endif
 
-	while (!_mtx_obtain_lock(m, tid)) {
+	for (;;) {
+		v = m->mtx_lock;
+		if (v == MTX_UNOWNED && _mtx_obtain_lock(m, tid))
+			break;
 #ifdef KDTRACE_HOOKS
 		spin_cnt++;
 #endif
@@ -428,7 +431,6 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts,
 		 * If the owner is running on another CPU, spin until the
 		 * owner stops running or the state of the lock changes.
 		 */
-		v = m->mtx_lock;
 		if (v != MTX_UNOWNED) {
 			owner = (struct thread *)(v & ~MTX_FLAGMASK);
 			if (TD_IS_RUNNING(owner)) {