diff --git a/sys/kern/kern_sx.c b/sys/kern/kern_sx.c
index 5408af4de4fa..994e584ceee4 100644
--- a/sys/kern/kern_sx.c
+++ b/sys/kern/kern_sx.c
@@ -48,6 +48,10 @@ struct lock_class lock_class_sx = {
 	LC_SLEEPLOCK | LC_SLEEPABLE | LC_RECURSABLE | LC_UPGRADABLE
 };
 
+#ifndef INVARIANTS
+#define	_sx_assert(sx, what, file, line)
+#endif
+
 void
 sx_init(struct sx *sx, const char *description)
 {
@@ -294,6 +298,10 @@ _sx_downgrade(struct sx *sx, const char *file, int line)
 }
 
 #ifdef INVARIANT_SUPPORT
+#ifndef INVARIANTS
+#undef	_sx_assert
+#endif
+
 /*
  * In the non-WITNESS case, sx_assert() can only detect that at least
  * *some* thread owns an slock, but it cannot guarantee that *this*
diff --git a/sys/sys/sx.h b/sys/sys/sx.h
index ba6b8b7bee00..67ccb320848e 100644
--- a/sys/sys/sx.h
+++ b/sys/sys/sx.h
@@ -70,11 +70,13 @@ void	_sx_assert(struct sx *sx, int what, const char *file, int line);
 #define	sx_try_upgrade(sx)	_sx_try_upgrade((sx), LOCK_FILE, LOCK_LINE)
 #define	sx_downgrade(sx)	_sx_downgrade((sx), LOCK_FILE, LOCK_LINE)
 
-#ifdef INVARIANTS
+#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
 #define	SX_LOCKED		LA_LOCKED
 #define	SX_SLOCKED		LA_SLOCKED
 #define	SX_XLOCKED		LA_XLOCKED
+#endif	/* INVARIANTS || INVARIANT_SUPPORT */
 
+#ifdef INVARIANTS
 #define	sx_assert(sx, what)	_sx_assert((sx), (what), LOCK_FILE, LOCK_LINE)
 #else	/* INVARIANTS */
 #define	sx_assert(sx, what)