diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index bbb5ebaf6..9216d90e8 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -4093,7 +4093,7 @@ Zotero.Item.prototype.toJSON = function (options = {}) {
 			if (linkMode == Zotero.Attachments.LINK_MODE_LINKED_FILE) {
 				obj.path = this.attachmentPath;
 			}
-			else {
+			else if (linkMode != Zotero.Attachments.LINK_MODE_LINKED_URL) {
 				obj.filename = this.attachmentFilename;
 			}
 			
diff --git a/test/tests/itemTest.js b/test/tests/itemTest.js
index 1a05fcbd5..a5a327ce0 100644
--- a/test/tests/itemTest.js
+++ b/test/tests/itemTest.js
@@ -986,6 +986,15 @@ describe("Zotero.Item", function () {
 				assert.isNull(json.mtime);
 				assert.isNull(json.md5);
 			})
+			
+			it("shouldn't include filename or path for linked_url attachments", function* () {
+				var item = new Zotero.Item('attachment');
+				item.attachmentLinkMode = 'linked_url';
+				item.url = "https://www.zotero.org/";
+				var json = item.toJSON();
+				assert.notProperty(json, "filename");
+				assert.notProperty(json, "path");
+			});
 		})
 		
 		describe("'full' mode", function () {