diff --git a/datasources/sources/gtfs_shape.rb b/datasources/sources/gtfs_shape.rb
index 3dca67e..62f3492 100644
--- a/datasources/sources/gtfs_shape.rb
+++ b/datasources/sources/gtfs_shape.rb
@@ -16,7 +16,8 @@ class Settings < GdalSource::Settings
       SELECT
         GUnion(DISTINCT shapes_geom.geometry) AS geometry,
         routes.*,
-        group_concat(DISTINCT stops.stop_name) AS stops
+        group_concat(DISTINCT stops.stop_name) AS stops,
+        group_concat(DISTINCT stops.stop_id||\'~\') AS stop_ids
       FROM
         shapes_geom
         JOIN trips ON
@@ -61,4 +62,8 @@ def map_tags(feat)
       },
     }
   end
+
+  def map_refs(feat)
+    feat['properties']['stop_ids']&.[](..-2)&.split('~,')
+  end
 end