diff --git a/web/gui/src/main/webapp/app/view/app/app.js b/web/gui/src/main/webapp/app/view/app/app.js
index 471bc43..7a7685b 100644
--- a/web/gui/src/main/webapp/app/view/app/app.js
+++ b/web/gui/src/main/webapp/app/view/app/app.js
@@ -407,11 +407,13 @@
 
                 // When an item is dragged over the document
                 var onDragOver = function (e) {
+                    d3.select('#frame').classed('dropping', true);
                     e.preventDefault();
                 };
 
                 // When the user leaves the window, cancels the drag or drops the item
                 var onDragEnd = function (e) {
+                    d3.select('#frame').classed('dropping', false);
                     e.preventDefault();
                 };