diff --git a/src/hb-open-type-private.hh b/src/hb-open-type-private.hh
index 71fb44e60..5afccbf08 100644
--- a/src/hb-open-type-private.hh
+++ b/src/hb-open-type-private.hh
@@ -113,7 +113,7 @@ inline Type& StructAfter(TObject &X)
  */
 
 /* Global nul-content Null pool.  Enlarge as necessary. */
-static const void *_NullPool[32 / sizeof (void *)];
+static const void *_NullPool[16 / sizeof (void *)];
 
 /* Generic nul-content Null objects. */
 template <typename Type>