diff --git a/modules/base.js b/modules/base.js
index fff7d4e4..856fab3d 100644
--- a/modules/base.js
+++ b/modules/base.js
@@ -335,7 +335,8 @@ var TreeStyleTabBase = inherit(TreeStyleTabConstants, {
 			);
 
 		if (button < 0)
-			button = 1;
+			return this.kGROUP_BOOKMARK_CANCEL;
+
 		var behaviors = [
 				this.kGROUP_BOOKMARK_SUBTREE | dummyTabFlag,
 				this.kGROUP_BOOKMARK_SEPARATE
diff --git a/modules/bookmark.js b/modules/bookmark.js
index 7883cb02..d3ad98e8 100644
--- a/modules/bookmark.js
+++ b/modules/bookmark.js
@@ -297,7 +297,8 @@ var TreeStyleTabBookmarksService = inherit(TreeStyleTabConstants, {
 		var TST = aBrowserWindow.TreeStyleTabService;
 
 		result.behavior = TST.openGroupBookmarkBehavior();
-		if (result.behavior & this.kGROUP_BOOKMARK_SUBTREE) {
+		if (result.behavior != this.kGROUP_BOOKMARK_CANCEL &&
+			result.behavior & this.kGROUP_BOOKMARK_SUBTREE) {
 			log('handleTabsOpenProcess: open as a group');
 			let treeStructure = result.behavior & this.kGROUP_BOOKMARK_DONT_RESTORE_TREE_STRUCTURE ?
 						null :
@@ -429,6 +430,9 @@ PlacesUIUtils._openTabset = function(aItemsToOpen, aEvent, aWindow, ...aArgs) {
 	var result = BS.handleTabsOpenProcess(where, aEvent, w, ids, uris, aItemsToOpen, this.__treestyletab__folderName);
 	log('  result: ', result);
 
+	if (result.behavior == this.kGROUP_BOOKMARK_CANCEL)
+		return;
+
 	var tabs = TST.doAndGetNewTabs((function() {
 			this.__treestyletab__openTabset(aItemsToOpen, aEvent, aWindow, ...aArgs);
 		}).bind(this), w.gBrowser);
diff --git a/modules/constants.js b/modules/constants.js
index a5e565a0..3b8945ec 100644
--- a/modules/constants.js
+++ b/modules/constants.js
@@ -235,6 +235,7 @@ var TreeStyleTabConstants = Object.freeze({
 	kGROUP_BOOKMARK_USE_DUMMY_FORCE             : 1024,
 	kGROUP_BOOKMARK_DONT_RESTORE_TREE_STRUCTURE : 512,
 	kGROUP_BOOKMARK_EXPAND_ALL_TREE             : 2048,
+	kGROUP_BOOKMARK_CANCEL    : -1,
 
 
 	CONTENT_SCRIPT          : 'chrome://treestyletab/content/content-utils.js',