diff --git a/toonz/sources/toonz/sceneviewerevents.cpp b/toonz/sources/toonz/sceneviewerevents.cpp
index 192f250..e4c5639 100644
--- a/toonz/sources/toonz/sceneviewerevents.cpp
+++ b/toonz/sources/toonz/sceneviewerevents.cpp
@@ -1516,10 +1516,14 @@ void SceneViewer::dragEnterEvent(QDragEnterEvent *event) {
 
   const QMimeData *mimeData = event->mimeData();
 
-  if (acceptResourceOrFolderDrop(mimeData->urls()))
-    event->acceptProposedAction();
-  else
-    event->ignore();
+  if (acceptResourceOrFolderDrop(mimeData->urls())) {
+	  // Force CopyAction
+	  event->setDropAction(Qt::CopyAction);
+	  event->accept();
+  }
+  else {
+	  event->ignore();
+  }
 }
 
 //-----------------------------------------------------------------------------