diff --git a/addons/website/static/src/js/content/snippets.animation.js b/addons/website/static/src/js/content/snippets.animation.js
index 1fcd167c66e..3d8fce7ca24 100644
--- a/addons/website/static/src/js/content/snippets.animation.js
+++ b/addons/website/static/src/js/content/snippets.animation.js
@@ -916,6 +916,10 @@ registry.backgroundVideo = publicWidget.Widget.extend(MobileYoutubeAutoplayMixin
         this.$iframe = this.$bgVideoContainer.find('.o_bg_video_iframe');
         this.$iframe.one('load', () => {
             this.$bgVideoContainer.find('.o_bg_video_loading').remove();
+            // When there is a "slide in (left or right) animation" element, we
+            // need to adjust the iframe size once it has been loaded, otherwise
+            // an horizontal scrollbar may appear.
+            this._adjustIframe();
         });
         this.$bgVideoContainer.prependTo(this.$el);
         $oldContainer.remove();