diff --git a/src/hb-common.h b/src/hb-common.h
index f5141b9ee..b6ce3f724 100644
--- a/src/hb-common.h
+++ b/src/hb-common.h
@@ -123,12 +123,13 @@ hb_direction_from_string (const char *str, int len);
 const char *
 hb_direction_to_string (hb_direction_t direction);
 
+#define HB_DIRECTION_IS_VALID(dir)	((((unsigned int) (dir)) & ~3U) == 4)
+/* Direction must be valid for the following */
 #define HB_DIRECTION_IS_HORIZONTAL(dir)	((((unsigned int) (dir)) & ~1U) == 4)
 #define HB_DIRECTION_IS_VERTICAL(dir)	((((unsigned int) (dir)) & ~1U) == 6)
 #define HB_DIRECTION_IS_FORWARD(dir)	((((unsigned int) (dir)) & ~2U) == 4)
 #define HB_DIRECTION_IS_BACKWARD(dir)	((((unsigned int) (dir)) & ~2U) == 5)
-#define HB_DIRECTION_IS_VALID(dir)	((((unsigned int) (dir)) & ~3U) == 4)
-#define HB_DIRECTION_REVERSE(dir)	((hb_direction_t) (((unsigned int) (dir)) ^ 1)) /* Direction must be valid */
+#define HB_DIRECTION_REVERSE(dir)	((hb_direction_t) (((unsigned int) (dir)) ^ 1))
 
 
 /* hb_language_t */