diff --git a/src/hb-open-type.hh b/src/hb-open-type.hh
index ee2723aad..896f7a015 100644
--- a/src/hb-open-type.hh
+++ b/src/hb-open-type.hh
@@ -282,9 +282,15 @@ struct OffsetTo : Offset<OffsetType, has_null>
   template <typename Base,
 	    hb_enable_if (hb_is_convertible (const Base, const void *))>
   friend const Type& operator + (const Base &base, const OffsetTo &offset) { return offset ((const void *) base); }
+  template <typename Base,
+	    hb_enable_if (hb_is_convertible (const Base, const void *))>
+  friend const Type& operator + (const OffsetTo &offset, const Base &base) { return offset ((const void *) base); }
   template <typename Base,
 	    hb_enable_if (hb_is_convertible (Base, void *))>
   friend Type& operator + (Base &&base, OffsetTo &offset) { return offset ((void *) base); }
+  template <typename Base,
+	    hb_enable_if (hb_is_convertible (Base, void *))>
+  friend Type& operator + (OffsetTo &offset, Base &&base) { return offset ((void *) base); }
 
   Type& serialize (hb_serialize_context_t *c, const void *base)
   {