Fix #2867

src/utils/popper.js

@@ -517,9 +517,17 @@
             var scrollParent = getScrollParent(this._popper);
             var offsetParentRect = getOffsetRect(offsetParent);
 
+			// Thanks the fucking native API, `document.body.scrollTop` & `document.documentElement.scrollTop`
+			var getScrollTopValue = function (element) {
+				return element == document.body ? Math.max(document.documentElement.scrollTop, document.body.scrollTop) : element.scrollTop;
+			}
+			var getScrollLeftValue = function (element) {
+				return element == document.body ? Math.max(document.documentElement.scrollLeft, document.body.scrollLeft) : element.scrollLeft;
+			}
+
             // if the popper is fixed we don't have to substract scrolling from the boundaries
-            var scrollTop = data.offsets.popper.position === 'fixed' ? 0 : scrollParent.scrollTop;
-            var scrollLeft = data.offsets.popper.position === 'fixed' ? 0 : scrollParent.scrollLeft;
+            var scrollTop = data.offsets.popper.position === 'fixed' ? 0 : getScrollTopValue(scrollParent);
+            var scrollLeft = data.offsets.popper.position === 'fixed' ? 0 : getScrollLeftValue(scrollParent);
 
             boundaries = {
                 top: 0 - (offsetParentRect.top - scrollTop),