diff --git a/src/libs/Navigation/AppNavigator/createCustomStackNavigator/CustomRouter.js b/src/libs/Navigation/AppNavigator/createCustomStackNavigator/CustomRouter.js
index 890db2b45ad4..42caad5b3969 100644
--- a/src/libs/Navigation/AppNavigator/createCustomStackNavigator/CustomRouter.js
+++ b/src/libs/Navigation/AppNavigator/createCustomStackNavigator/CustomRouter.js
@@ -12,11 +12,11 @@ const isAtLeastOneCentralPaneNavigatorInState = (state) => _.find(state.routes,
 
 /**
  * @param {Object} state - react-navigation state
- * @returns {String|undefined}
+ * @returns {String}
  */
 const getTopMostReportIDFromRHP = (state) => {
     if (!state) {
-        return;
+        return '';
     }
     const topmostRightPane = lodashFindLast(state.routes, (route) => route.name === NAVIGATORS.RIGHT_MODAL_NAVIGATOR);
 
@@ -33,6 +33,8 @@ const getTopMostReportIDFromRHP = (state) => {
     if (topmostRoute.params && topmostRoute.params.reportID) {
         return topmostRoute.params.reportID;
     }
+
+    return '';
 };
 /**
  * Adds report route without any specific reportID to the state.