diff --git a/addons/website/static/src/snippets/s_image_gallery/options.js b/addons/website/static/src/snippets/s_image_gallery/options.js
index 96dd8a988fe..54fbf819ba8 100644
--- a/addons/website/static/src/snippets/s_image_gallery/options.js
+++ b/addons/website/static/src/snippets/s_image_gallery/options.js
@@ -202,6 +202,8 @@ options.registry.gallery = options.registry.CarouselHandler.extend({
             cols.forEach((col) => {
                 var $col = $(col);
                 var height = $col.is(':empty') ? 0 : $col.find('img').last().offset().top + $col.find('img').last().height() - self.$target.offset().top;
+                // Neutralize invisible sub-pixel height differences.
+                height = Math.round(height);
                 if (height < min) {
                     min = height;
                     $lowest = $col;