diff --git a/addons/website/static/src/snippets/s_countdown/000.js b/addons/website/static/src/snippets/s_countdown/000.js
index d83a8f7d227..d9a9ab5dbd4 100644
--- a/addons/website/static/src/snippets/s_countdown/000.js
+++ b/addons/website/static/src/snippets/s_countdown/000.js
@@ -23,6 +23,17 @@ const CountdownWidget = publicWidget.Widget.extend({
         this.endTime = parseInt(this.el.dataset.endTime);
         this.size = parseInt(this.el.dataset.size);
         this.display = this.el.dataset.display;
+        if (!this.display && this.el.dataset.bsDisplay) {
+            // With the BS5 upgrade script of 16.0, countdowns' data-display may
+            // have been converted to data-bs-display by mistake. This will fix
+            // the DOM for good measures, maybe even allowing to remove this
+            // code in a few years as hopefully all current countdowns will have
+            // been removed or edited (or when a proper upgrade script in a
+            // future version of Odoo will be made, if necessary). TODO.
+            this.display = this.el.dataset.bsDisplay;
+            delete this.el.dataset.bsDisplay;
+            this.el.dataset.display = this.display;
+        }
 
         this.layout = this.el.dataset.layout;
         this.layoutBackground = this.el.dataset.layoutBackground;