diff --git a/src/hb-ot-map-private.hh b/src/hb-ot-map-private.hh
index 710cc0af4..5675d37a7 100644
--- a/src/hb-ot-map-private.hh
+++ b/src/hb-ot-map-private.hh
@@ -125,6 +125,9 @@ struct hb_ot_map_t
 			  void *face_or_font,
 			  hb_buffer_t *buffer) const;
 
+  HB_INTERNAL void substitute_closure (hb_face_t *face,
+				       hb_glyph_map_t *glyphs) const;
+
   hb_mask_t global_mask;
 
   hb_tag_t chosen_script[2];
diff --git a/src/hb-ot-map.cc b/src/hb-ot-map.cc
index a54e306e8..a0efe900b 100644
--- a/src/hb-ot-map.cc
+++ b/src/hb-ot-map.cc
@@ -95,6 +95,21 @@ void hb_ot_map_t::apply (unsigned int table_index,
     apply_lookup_func (face_or_font, buffer, lookups[table_index][i].index, lookups[table_index][i].mask);
 }
 
+void hb_ot_map_t::substitute_closure (hb_face_t *face,
+				      hb_glyph_map_t *glyphs) const
+{
+  unsigned int table_index = 0;
+  unsigned int i = 0;
+
+  for (unsigned int pause_index = 0; pause_index < pauses[table_index].len; pause_index++) {
+    const pause_map_t *pause = &pauses[table_index][pause_index];
+    for (; i < pause->num_lookups; i++)
+      hb_ot_layout_substitute_closure_lookup (face, glyphs, lookups[table_index][i].index);
+  }
+
+  for (; i < lookups[table_index].len; i++)
+    hb_ot_layout_substitute_closure_lookup (face, glyphs, lookups[table_index][i].index);
+}
 
 void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func, void *user_data)
 {