diff --git a/client/src/mvc/library/library-foldertoolbar-view.js b/client/src/mvc/library/library-foldertoolbar-view.js
index 3955e91c03f..2f0f2390dac 100644
--- a/client/src/mvc/library/library-foldertoolbar-view.js
+++ b/client/src/mvc/library/library-foldertoolbar-view.js
@@ -666,7 +666,8 @@ var FolderToolbarView = Backbone.View.extend({
             this.modal.disableButton("Import");
             for (let i = selected_nodes.length - 1; i >= 0; i--) {
                 if (selected_nodes[i].li_attr.full_path !== undefined) {
-                    paths.push(selected_nodes[i].li_attr.full_path);
+                    // should be always String
+                    paths.push(`"${selected_nodes[i].li_attr.full_path}"`);
                 }
             }
             this.initChainCallControl({
diff --git a/lib/galaxy/webapps/galaxy/api/library_datasets.py b/lib/galaxy/webapps/galaxy/api/library_datasets.py
index 7e1a8a4b38f..35c5d45f715 100644
--- a/lib/galaxy/webapps/galaxy/api/library_datasets.py
+++ b/lib/galaxy/webapps/galaxy/api/library_datasets.py
@@ -396,6 +396,9 @@ class LibraryDatasetsController(BaseAPIController, UsesVisualizationMixin, Libra
         path = kwd.get('path', None)
         if path is None:
             raise exceptions.RequestParameterMissingException('The required attribute path is missing.')
+        if not isinstance(path, str):
+            raise exceptions.RequestParameterInvalidException('The required attribute path is not String.')
+
         folder = self.folder_manager.get(trans, folder_id)
 
         source = kwd.get('source', None)