diff --git a/src/hb-ot-layout-common.hh b/src/hb-ot-layout-common.hh
index 0a4b1ecf7..7b466fb0b 100644
--- a/src/hb-ot-layout-common.hh
+++ b/src/hb-ot-layout-common.hh
@@ -2548,9 +2548,9 @@ struct SparseVarRegionAxis
   DEFINE_SIZE_STATIC (8);
 };
 
-#define REGION_CACHE_ITEM_CACHE_INVALID (-1 << 31)
-#define REGION_CACHE_ITEM_MULTIPLIER (float (1 << 30))
-#define REGION_CACHE_ITEM_DIVISOR (1.f / float (1 << 30))
+#define REGION_CACHE_ITEM_CACHE_INVALID INT_MIN
+#define REGION_CACHE_ITEM_MULTIPLIER (float (1 << ((sizeof (int) * 8) - 2)))
+#define REGION_CACHE_ITEM_DIVISOR (1.f / float (1 << ((sizeof (int) * 8) - 2)))
 
 struct VarRegionList
 {