diff --git a/src/hb-ot-map.hh b/src/hb-ot-map.hh
index 40b9921fd..fde85b1dd 100644
--- a/src/hb-ot-map.hh
+++ b/src/hb-ot-map.hh
@@ -162,7 +162,7 @@ struct hb_ot_map_t
   hb_mask_t global_mask;
 
   hb_vector_t<feature_map_t, 8> features;
-  hb_vector_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
+  hb_vector_t<lookup_map_t, 16> lookups[2]; /* GSUB/GPOS */
   hb_vector_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */
 };