diff --git a/src/agenda/AgendaView.js b/src/agenda/AgendaView.js
index d44d4f9..3210216 100644
--- a/src/agenda/AgendaView.js
+++ b/src/agenda/AgendaView.js
@@ -647,7 +647,7 @@ function AgendaView(element, calendar, viewName) {
 	
 	
 	function slotSelectionMousedown(ev) {
-		if (opt('selectable')) {
+		if (ev.which == 1 && opt('selectable')) { // ev.which==1 means left mouse button
 			unselect(ev);
 			var _mousedownElement = this;
 			var dates;
diff --git a/src/common/SelectionManager.js b/src/common/SelectionManager.js
index c461990..afb3616 100644
--- a/src/common/SelectionManager.js
+++ b/src/common/SelectionManager.js
@@ -68,7 +68,7 @@ function SelectionManager() {
 		var cellDate = t.cellDate;
 		var cellIsAllDay = t.cellIsAllDay;
 		var hoverListener = t.getHoverListener();
-		if (opt('selectable')) {
+		if (ev.which == 1 && opt('selectable')) { // which==1 means left mouse button
 			unselect(ev);
 			var _mousedownElement = this;
 			var dates;