diff --git a/chrome/content/zotero/xpcom/data/collection.js b/chrome/content/zotero/xpcom/data/collection.js
index bbbbf6009..3a0f5bf75 100644
--- a/chrome/content/zotero/xpcom/data/collection.js
+++ b/chrome/content/zotero/xpcom/data/collection.js
@@ -80,7 +80,8 @@ Zotero.defineProperty(Zotero.Collection.prototype, 'parent', {
 	set: function(val) {
 		Zotero.debug("WARNING: Zotero.Collection.prototype.parent has been deprecated -- use .parentID or .parentKey", 2);
 		this.parentID = val;
-	}
+	},
+	enumerable: false
 });
 
 Zotero.defineProperty(Zotero.Collection.prototype, 'treeViewID', {
diff --git a/chrome/content/zotero/xpcom/data/feed.js b/chrome/content/zotero/xpcom/data/feed.js
index 840059209..9a4baec33 100644
--- a/chrome/content/zotero/xpcom/data/feed.js
+++ b/chrome/content/zotero/xpcom/data/feed.js
@@ -114,6 +114,11 @@ Zotero.defineProperty(Zotero.Feed.prototype, 'isFeed', {
 Zotero.defineProperty(Zotero.Feed.prototype, 'libraryTypes', {
 	value: Object.freeze(Zotero.Feed._super.prototype.libraryTypes.concat(['feed']))
 });
+
+Zotero.defineProperty(Zotero.Feed.prototype, 'libraryTypeID', {
+	get: () => undefined
+});
+
 Zotero.defineProperty(Zotero.Feed.prototype, 'unreadCount', {
 	get: function() { return this._feedUnreadCount; }
 });
diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index 3ecab174f..be389764b 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -105,7 +105,8 @@ Zotero.defineProperty(Zotero.Item.prototype, 'itemID', {
 	get: function() {
 		Zotero.debug("Item.itemID is deprecated -- use Item.id");
 		return this._id;
-	}
+	},
+	enumerable: false
 });
 Zotero.defineProperty(Zotero.Item.prototype, 'libraryID', {
 	get: function() { return this._libraryID; },
@@ -2685,7 +2686,8 @@ Zotero.defineProperty(Zotero.Item.prototype, 'attachmentMIMEType', {
 	get: function() {
 		Zotero.debug(".attachmentMIMEType deprecated -- use .attachmentContentType");
 		return this.attachmentContentType;
-	}
+	},
+	enumerable: false
 });
 
 /**
diff --git a/chrome/content/zotero/xpcom/data/library.js b/chrome/content/zotero/xpcom/data/library.js
index 6abcb4be0..153fd5a7d 100644
--- a/chrome/content/zotero/xpcom/data/library.js
+++ b/chrome/content/zotero/xpcom/data/library.js
@@ -142,7 +142,7 @@ Zotero.defineProperty(Zotero.Library.prototype, 'libraryTypeID', {
 			return Zotero.Groups.getGroupIDFromLibraryID(this._libraryID);
 		
 		default:
-			throw new Error(`Cannot return library type id for ${this._libraryType} library`);
+			throw new Error(`Tried to get library type id for ${this._libraryType} library`);
 		}
 	}
 });
@@ -169,6 +169,7 @@ Zotero.defineProperty(Zotero.Library.prototype, 'name', {
 			return Zotero.getString('pane.collections.library');
 		}
 		
+		// This property is provided by the extending objects (Group, Feed) for other library types
 		throw new Error('Unhandled library type "' + this._libraryType + '"');
 	}
 });
diff --git a/test/tests/feedTest.js b/test/tests/feedTest.js
index 90d3fa25e..15e793798 100644
--- a/test/tests/feedTest.js
+++ b/test/tests/feedTest.js
@@ -50,6 +50,13 @@ describe("Zotero.Feed", function() {
 		});
 	});
 	
+	describe("#libraryTypeID", function () {
+		it("should be undefind", function* () {
+			let feed = yield createFeed();
+			assert.isUndefined(feed.libraryTypeID);
+		});
+	});
+	
 	describe("#url", function() {
 		it("should throw if trying to set an invalid URL", function *() {
 			let feed = new Zotero.Feed({ name: 'Test ' + Zotero.randomString() });