diff --git a/lib/web/mage/calendar.js b/lib/web/mage/calendar.js
index d78c8fd2b5cf1..3be1ace78b26f 100644
--- a/lib/web/mage/calendar.js
+++ b/lib/web/mage/calendar.js
@@ -104,7 +104,8 @@ define([
 
         _overwriteFindPos: function () {
             $.datepicker.constructor.prototype._findPos = function (obj) {
-                var position = $(obj).offset();
+                let isInModalSlide = $(obj).closest('.modal-slide').length > 0,
+                    position = isInModalSlide ? obj.getBoundingClientRect() : $(obj).offset();
 
                 return [position.left, position.top];
             };