diff --git a/lib/internal/inspector/webstorage.js b/lib/internal/inspector/webstorage.js
index 2bb6f5e6f8c743..6cba87b236ed12 100644
--- a/lib/internal/inspector/webstorage.js
+++ b/lib/internal/inspector/webstorage.js
@@ -7,6 +7,8 @@ const { getOptionValue } = require('internal/options');
 
 class InspectorLocalStorage extends Storage {
   setItem(key, value) {
+    key = `${key}`;
+    value = `${value}`;
     const oldValue = this.getItem(key);
     super.setItem(key, value);
     if (oldValue == null) {
@@ -17,6 +19,7 @@ class InspectorLocalStorage extends Storage {
   }
 
   removeItem(key) {
+    key = `${key}`;
     super.removeItem(key);
     itemRemoved(key, true);
   }
@@ -29,6 +32,8 @@ class InspectorLocalStorage extends Storage {
 
 const InspectorSessionStorage = class extends Storage {
   setItem(key, value) {
+    key = `${key}`;
+    value = `${value}`;
     const oldValue = this.getItem(key);
     super.setItem(key, value);
     if (oldValue == null) {
@@ -39,6 +44,7 @@ const InspectorSessionStorage = class extends Storage {
   }
 
   removeItem(key) {
+    key = `${key}`;
     super.removeItem(key);
     itemRemoved(key, false);
   }