diff --git a/src/hb-ot-map-private.hh b/src/hb-ot-map-private.hh
index 22ea8ba..7eb85c8 100644
--- a/src/hb-ot-map-private.hh
+++ b/src/hb-ot-map-private.hh
@@ -49,6 +49,7 @@
     unsigned int shift;
     hb_mask_t mask;
     hb_mask_t _1_mask; /* mask for value=1, for quick access */
+    hb_bool_t needs_fallback;
 
     static int cmp (const feature_map_t *a, const feature_map_t *b)
     { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
@@ -80,6 +81,11 @@
     return map ? map->mask : 0;
   }
 
+  inline bool needs_fallback (hb_tag_t feature_tag) const {
+    const feature_map_t *map = features.bsearch (&feature_tag);
+    return map ? map->needs_fallback : false;
+  }
+
   inline hb_mask_t get_1_mask (hb_tag_t feature_tag) const {
     const feature_map_t *map = features.bsearch (&feature_tag);
     return map ? map->_1_mask : 0;