diff --git a/src/hb-machinery.hh b/src/hb-machinery.hh
index 54bc60d4c..3bd5a979b 100644
--- a/src/hb-machinery.hh
+++ b/src/hb-machinery.hh
@@ -80,6 +80,11 @@ static inline Type& StructAfter(TObject &X)
  * Size checking
  */
 
+/* Size signifying variable-sized array */
+#ifndef HB_VAR_ARRAY
+#define HB_VAR_ARRAY 1
+#endif
+
 /* Check _assertion in a method environment */
 #define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \
   void _instance_assertion_on_line_##_line () const \
diff --git a/src/hb.hh b/src/hb.hh
index fd893d5fc..5915e2819 100644
--- a/src/hb.hh
+++ b/src/hb.hh
@@ -448,11 +448,6 @@ static_assert ((sizeof (hb_mask_t) == 4), "");
 static_assert ((sizeof (hb_var_int_t) == 4), "");
 
 
-/* Size signifying variable-sized array */
-#ifndef HB_VAR_ARRAY
-#define HB_VAR_ARRAY 1
-#endif
-
 static inline float
 _hb_roundf (float x) { return floorf (x + .5f); }
 #define roundf(x) _hb_roundf(x)