diff --git a/src/playground/player.jsx b/src/playground/player.jsx
index b20bafc52c46736f3586ae0134947e759df4e74f..6c2833f1b8108d08022e9d6c85bac9357f1f497f 100644
--- a/src/playground/player.jsx
+++ b/src/playground/player.jsx
@@ -36,7 +36,7 @@ const Player = ({isPlayerOnly, onSeeInside, projectId}) => (
 Player.propTypes = {
     isPlayerOnly: PropTypes.bool,
     onSeeInside: PropTypes.func,
-    projectId: PropTypes.number
+    projectId: PropTypes.string
 };
 
 const mapStateToProps = state => ({