diff --git a/src/datepicker.jsx b/src/datepicker.jsx
index aa5776455..8d9d4396b 100644
--- a/src/datepicker.jsx
+++ b/src/datepicker.jsx
@@ -147,6 +147,7 @@ var DatePicker = React.createClass({
 
   handleCalendarClickOutside (event) {
     this.setOpen(false)
+    if (this.props.withPortal) { event.preventDefault() }
   },
 
   handleSelect (date, event) {