diff --git a/src/include/storage/s_lock.h b/src/include/storage/s_lock.h
index ce45ffe..a7e0436 100644
--- a/src/include/storage/s_lock.h
+++ b/src/include/storage/s_lock.h
@@ -199,6 +199,7 @@ spin_delay(void)
 typedef unsigned char slock_t;
 
 #define TAS(lock) tas(lock)
+#define TAS_SPIN(lock)	(*(lock) ? 1 : TAS(lock))
 
 static __inline__ int
 tas(volatile slock_t *lock)