diff --git a/sys/sys/lock.h b/sys/sys/lock.h
--- a/sys/sys/lock.h
+++ b/sys/sys/lock.h
@@ -325,6 +325,7 @@
 #define	WITNESS_RELEASEOK(lock)					(void)0
 #define	WITNESS_FILE(lock) ("?")
 #define	WITNESS_LINE(lock) (0)
+#define	WITNESS_BLESSED(uniquifier, lock1, lock2)
 #endif	/* WITNESS */
 
 #endif	/* _KERNEL */