diff --git a/src/hb-machinery.hh b/src/hb-machinery.hh
index 24e454416..2f57fb6b4 100644
--- a/src/hb-machinery.hh
+++ b/src/hb-machinery.hh
@@ -100,24 +100,28 @@ static inline Type& StructAfter(TObject &X)
   DEFINE_INSTANCE_ASSERTION (alignof (*this) == 1 && \
 			     sizeof (*this) == (size)); \
   inline unsigned int get_size (void) const { return (size); } \
-  enum { static_size = (size) }; \
-  enum { min_size = (size) }
+  enum { null_size = (size) }; \
+  enum { min_size = (size) }; \
+  enum { static_size = (size) }
 
 #define DEFINE_SIZE_UNION(size, _member) \
   DEFINE_COMPILES_ASSERTION ((void) this->u._member.static_size); \
   DEFINE_INSTANCE_ASSERTION (alignof (*this) == 1 && \
 			     sizeof(this->u._member) == (size)); \
+  enum { null_size = (size) }; \
   enum { min_size = (size) }
 
 #define DEFINE_SIZE_MIN(size) \
   DEFINE_INSTANCE_ASSERTION (alignof (*this) == 1 && \
 			     sizeof (*this) >= (size)); \
+  enum { null_size = (size) }; \
   enum { min_size = (size) }
 
 #define DEFINE_SIZE_ARRAY(size, array) \
   DEFINE_COMPILES_ASSERTION ((void) (array)[0].static_size); \
   DEFINE_INSTANCE_ASSERTION (alignof (*this) == 1 && \
 			     sizeof (*this) == (size) + VAR * sizeof ((array)[0])); \
+  enum { null_size = (size) }; \
   enum { min_size = (size) }
 
 #define DEFINE_SIZE_ARRAY_SIZED(size, array) \
diff --git a/src/hb-null.hh b/src/hb-null.hh
index 25a24f05c..51f653d2a 100644
--- a/src/hb-null.hh
+++ b/src/hb-null.hh
@@ -52,7 +52,7 @@ static inline Type const & Null (void) {
 /* Specializations for arbitrary-content Null objects expressed in bytes. */
 #define DECLARE_NULL_NAMESPACE_BYTES(Namespace, Type) \
 	} /* Close namespace. */ \
-	extern HB_INTERNAL const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::min_size]; \
+	extern HB_INTERNAL const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::null_size]; \
 	template <> \
 	/*static*/ inline const Namespace::Type& Null<Namespace::Type> (void) { \
 	  return *reinterpret_cast<const Namespace::Type *> (_hb_Null_##Namespace##_##Type); \
@@ -60,7 +60,7 @@ static inline Type const & Null (void) {
 	namespace Namespace { \
 	static_assert (true, "Just so we take semicolon after.")
 #define DEFINE_NULL_NAMESPACE_BYTES(Namespace, Type) \
-	const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::min_size]
+	const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::null_size]
 
 /* Specializations for arbitrary-content Null objects expressed as struct initializer. */
 #define DECLARE_NULL_INSTANCE(Type) \