diff --git a/index.js b/index.js
index cbd32c5..e795f6f 100644
--- a/index.js
+++ b/index.js
@@ -58,7 +58,7 @@ export default class SearchableDropDown extends Component {
   componentDidMount = () => {
     const listItems = this.props.items;
     const defaultIndex = this.props.defaultIndex;
-    if (defaultIndex && listItems.length > defaultIndex) {
+    if (!isNaN(defaultIndex) && listItems.length > defaultIndex) {
       this.setState({
         listItems,
         item: listItems[defaultIndex]