diff --git a/umap/static/umap/js/umap.popup.js b/umap/static/umap/js/umap.popup.js
index 6c85ba57..0ab65b1e 100644
--- a/umap/static/umap/js/umap.popup.js
+++ b/umap/static/umap/js/umap.popup.js
@@ -96,6 +96,7 @@ U.Popup.Panel = U.Popup.extend({
   _updateLayout: function () {},
   _updatePosition: function () {},
   _adjustPan: function () {},
+  _animateZoom: function () {},
 })
 U.Popup.SimplePanel = U.Popup.Panel // Retrocompat.