diff --git a/src/hb-ot-map-private.hh b/src/hb-ot-map-private.hh
index 2c8b99f61..07a321f6c 100644
--- a/src/hb-ot-map-private.hh
+++ b/src/hb-ot-map-private.hh
@@ -42,16 +42,7 @@ struct hb_ot_map_builder_t
 {
   public:
 
-  inline void add_feature (hb_tag_t tag, unsigned int value, bool global)
-  {
-    feature_info_t *info = feature_infos.push();
-    if (unlikely (!info)) return;
-    info->tag = tag;
-    info->seq = feature_infos.len;
-    info->max_value = value;
-    info->global = global;
-    info->default_value = global ? value : 0;
-  }
+  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value, bool global);
 
   inline void add_bool_feature (hb_tag_t tag, bool global = true)
   { add_feature (tag, 1, global); }
diff --git a/src/hb-ot-map.cc b/src/hb-ot-map.cc
index f178bed84..68e1321f8 100644
--- a/src/hb-ot-map.cc
+++ b/src/hb-ot-map.cc
@@ -64,6 +64,17 @@ hb_ot_map_t::add_lookups (hb_face_t    *face,
 }
 
 
+void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value, bool global)
+{
+  feature_info_t *info = feature_infos.push();
+  if (unlikely (!info)) return;
+  info->tag = tag;
+  info->seq = feature_infos.len;
+  info->max_value = value;
+  info->global = global;
+  info->default_value = global ? value : 0;
+}
+
 void
 hb_ot_map_builder_t::compile (hb_face_t *face,
 			      const hb_segment_properties_t *props,