diff --git a/src/hb-font-private.hh b/src/hb-font-private.hh
index 3a42f0766..c87ad5856 100644
--- a/src/hb-font-private.hh
+++ b/src/hb-font-private.hh
@@ -461,7 +461,7 @@ struct hb_font_t {
   }
 
   private:
-  inline hb_position_t em_scale (int16_t v, int scale) { return v * (int64_t) scale / hb_face_get_upem (this->face); }
+  inline hb_position_t em_scale (int16_t v, int scale) { return v * (int64_t) scale / face->get_upem (); }
 };
 
 #define HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS