diff --git a/package.json b/package.json
index 8a55947..eafb5cf 100644
--- a/package.json
+++ b/package.json
@@ -34,6 +34,9 @@
   ],
   "author": "Jack Hsu <jack.hsu@gmail.com> (http://jaysoo.ca/)",
   "license": "ISC",
+  "dependencies": {
+    "prop-types": "^15.6.0"
+  },
   "devDependencies": {
     "appium": "^1.4.16",
     "babel-core": "^6.4.0",
diff --git a/src/Prompt.js b/src/Prompt.js
index d778d0a..cb45cdc 100644
--- a/src/Prompt.js
+++ b/src/Prompt.js
@@ -1,4 +1,4 @@
-import React, { Component, PropTypes } from 'react';
+import React, { Component } from 'react';
 import {
   Modal,
   Platform,
@@ -7,6 +7,7 @@ import {
   TouchableWithoutFeedback,
   View
 } from 'react-native';
+import PropTypes from 'prop-types';
 import styles from './styles';
 
 export default class Prompt extends Component {
@@ -15,11 +16,12 @@ export default class Prompt extends Component {
     visible: PropTypes.bool,
     defaultValue: PropTypes.string,
     placeholder: PropTypes.string,
-    onCancel: PropTypes.func.isRequired,
+    onCancel: PropTypes.func,
     cancelText: PropTypes.string,
+    cancelable: PropTypes.bool,
     onSubmit: PropTypes.func.isRequired,
     submitText: PropTypes.string,
-    onChangeText: PropTypes.func.isRequired,
+    onChangeText: PropTypes.func,
     borderColor: PropTypes.string,
     promptStyle: PropTypes.object,
     titleStyle: PropTypes.object,
@@ -45,6 +47,7 @@ export default class Prompt extends Component {
     buttonTextStyle: {},
     submitButtonStyle: {},
     submitButtonTextStyle: {},
+    cancelable: true,
     cancelButtonStyle: {},
     cancelButtonTextStyle: {},
     inputStyle: {},