diff --git a/frontend/src/uxbox/main/ui/workspace/sortable.cljs b/frontend/src/uxbox/main/ui/workspace/sortable.cljs
index 823433602..e217ababa 100644
--- a/frontend/src/uxbox/main/ui/workspace/sortable.cljs
+++ b/frontend/src/uxbox/main/ui/workspace/sortable.cljs
@@ -22,14 +22,14 @@
         [_, drop] (rdnd/useDrop
                    #js {:accept type
                         :hover (fn [item monitor]
-                                 (when (.-current ref)
+                                 (when (unchecked-get ref "current")
                                    (on-hover (unchecked-get item "data") monitor)))
                         :drop (fn [item monitor]
-                                (when (.-current ref)
+                                (when (unchecked-get ref "current")
                                   (on-drop (unchecked-get item "data") monitor)))})
         [props, drag] (rdnd/useDrag
                        #js {:item #js {:type type :data data}
-                            :collect (fn [monitor]
+                            :collect (fn [^js/ReactDnd.Monitor monitor]
                                        #js {:dragging? (.isDragging monitor)})})]
     [(mfu/obj->map props)
      (drag (drop ref))]))
diff --git a/frontend/tools.clj b/frontend/tools.clj
index 88817f1c2..dd37087ec 100644
--- a/frontend/tools.clj
+++ b/frontend/tools.clj
@@ -30,6 +30,7 @@
    :language-out :ecmascript5
    :closure-defines closure-defines
    :optimizations :none
+   :infer-externs true
    :verbose true
    :source-map true
    :static-fns false
diff --git a/frontend/vendor/react-dnd/externs.js b/frontend/vendor/react-dnd/externs.js
index 223a8e564..87aa30e26 100644
--- a/frontend/vendor/react-dnd/externs.js
+++ b/frontend/vendor/react-dnd/externs.js
@@ -1,4 +1,7 @@
 var ReactDnd = {};
+ReactDnd.Monitor = function() {}
+ReactDnd.Monitor.prototype.isDragging = function() {}
+
 ReactDnd.useDrag = function() {};
 ReactDnd.useDrop = function() {};
 ReactDnd.DndProvider = function() {};