diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index c0441268897..3ada9246326 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -288,7 +288,7 @@ __mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, int line)
 	    curthread, m->lock_object.lo_name, file, line));
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("mtx_lock() of destroyed mutex @ %s:%d", file, line));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_spin,
 	    ("mtx_lock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
 	    file, line));
 	WITNESS_CHECKORDER(&m->lock_object, (opts & ~MTX_RECURSE) |
@@ -317,7 +317,7 @@ __mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, int line)
 
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("mtx_unlock() of destroyed mutex @ %s:%d", file, line));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_spin,
 	    ("mtx_unlock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
 	    file, line));
 	WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
@@ -346,7 +346,7 @@ __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file,
 
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("mtx_lock_spin() of destroyed mutex @ %s:%d", file, line));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_sleep,
 	    ("mtx_lock_spin() of sleep mutex %s @ %s:%d",
 	    m->lock_object.lo_name, file, line));
 	if (mtx_owned(m))
@@ -387,7 +387,7 @@ __mtx_trylock_spin_flags(volatile uintptr_t *c, int opts, const char *file,
 
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("mtx_trylock_spin() of destroyed mutex @ %s:%d", file, line));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_sleep,
 	    ("mtx_trylock_spin() of sleep mutex %s @ %s:%d",
 	    m->lock_object.lo_name, file, line));
 	KASSERT((opts & MTX_RECURSE) == 0,
@@ -412,7 +412,7 @@ __mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, const char *file,
 
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_sleep,
 	    ("mtx_unlock_spin() of sleep mutex %s @ %s:%d",
 	    m->lock_object.lo_name, file, line));
 	WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line);
@@ -450,7 +450,7 @@ _mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF)
 	    curthread, m->lock_object.lo_name, file, line));
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("mtx_trylock() of destroyed mutex @ %s:%d", file, line));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_spin,
 	    ("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name,
 	    file, line));
 
@@ -827,7 +827,7 @@ thread_lock_validate(struct mtx *m, int opts, const char *file, int line)
 
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("thread_lock() of destroyed mutex @ %s:%d", file, line));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_sleep,
 	    ("thread_lock() of sleep mutex %s @ %s:%d",
 	    m->lock_object.lo_name, file, line));
 	KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) == 0,
@@ -1286,7 +1286,7 @@ mtx_spin_wait_unlocked(struct mtx *m)
 
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("%s() of destroyed mutex %p", __func__, m));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_sleep,
 	    ("%s() of sleep mutex %p (%s)", __func__, m,
 	    m->lock_object.lo_name));
 	KASSERT(!mtx_owned(m), ("%s() waiting on myself on lock %p (%s)", __func__, m,
@@ -1312,8 +1312,8 @@ mtx_wait_unlocked(struct mtx *m)
 
 	KASSERT(m->mtx_lock != MTX_DESTROYED,
 	    ("%s() of destroyed mutex %p", __func__, m));
-	KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep,
-	    ("%s() not a sleep mutex %p (%s)", __func__, m,
+	KASSERT(LOCK_CLASS(&m->lock_object) != &lock_class_mtx_spin,
+	    ("%s() of spin mutex %p (%s)", __func__, m,
 	    m->lock_object.lo_name));
 	KASSERT(!mtx_owned(m), ("%s() waiting on myself on lock %p (%s)", __func__, m,
 	    m->lock_object.lo_name));