diff --git a/src/hb-aat-layout-opbd-table.hh b/src/hb-aat-layout-opbd-table.hh
index 5b9c39125..80ed10347 100644
--- a/src/hb-aat-layout-opbd-table.hh
+++ b/src/hb-aat-layout-opbd-table.hh
@@ -45,10 +45,10 @@ struct OpticalBounds
     return_trace (likely (c->check_struct (this)));
   }
 
-  HBINT16	leftSide;
-  HBINT16	topSide;
-  HBINT16	rightSide;
-  HBINT16	bottomSide;
+  FWORD		leftSide;
+  FWORD		topSide;
+  FWORD		rightSide;
+  FWORD		bottomSide;
   public:
   DEFINE_SIZE_STATIC (8);
 };