diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7172050c..cb0c255e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,8 +4,8 @@
 
 ### Minor changes and fixes
 
-* Anonymous chat user: remember the chosen nickname in sessionStorage, to avoid entering it again too often.
-* Fix: if an anonymous chat user enter spaces in the nickname choice, it will allows them to keep the random nickname.
+* Anonymous chat user: remember the chosen nickname in localStorage, to avoid entering it again too often. Nickname will expire after 12 hours.
+* Fix: if an anonymous chat user enter spaces in the nickname choice, it allowed them to keep the random nickname.
 * Authenticated users: if current user nickname is already used in the room, automatically add a suffix.
 * UX: add a label ('Choose a nickname to enter') for the anonymous nickname prompt. Fix #287.
 * Translation updates: German, French.
diff --git a/conversejs/lib/nick.ts b/conversejs/lib/nick.ts
index d8e3b9f3..5eeb7b48 100644
--- a/conversejs/lib/nick.ts
+++ b/conversejs/lib/nick.ts
@@ -10,12 +10,28 @@ function randomNick (base: string): string {
 }
 
 /**
- * Get the previous anonymous nickname (stored in sessionStorage).
+ * Get the previous anonymous nickname (stored in localStorage).
+ * If it was set more than 12 hours ago, it will be ignored (considering the nickname should not remain forever).
  * @returns previous nickname or null
  */
 function getPreviousAnonymousNick (): string | null {
   try {
-    return sessionStorage.getItem('livechat-previous-anonymous-nickname')
+    const lastAccess = parseInt(localStorage.getItem('livechat-previous-anonymous-nickname-last-access') ?? '0')
+    const now = Date.now()
+    if (lastAccess && !isNaN(lastAccess)) {
+      const expires = lastAccess + 1000 * 60 * 60 * 12 // nickname expires after 12 hours
+      if (now > expires) {
+        console.log('Anonymous nickname has expired.')
+        localStorage.removeItem('livechat-previous-anonymous-nickname')
+        localStorage.removeItem('livechat-previous-anonymous-nickname-last-access')
+        return null
+      }
+    }
+    const nick = localStorage.getItem('livechat-previous-anonymous-nickname')
+    if (nick !== null) {
+      localStorage.setItem('livechat-previous-anonymous-nickname-last-access', now.toString())
+    }
+    return nick
   } catch (err) {
     console.error(err)
     return null
@@ -23,12 +39,13 @@ function getPreviousAnonymousNick (): string | null {
 }
 
 /**
- * Stores the chosen nickname in sessionStorage.
+ * Stores the chosen nickname in localStorage.
  */
 function setPreviousAnonymousNick (nick: string): void {
   try {
     console.log('Storing anonymous nickname', nick)
-    sessionStorage.setItem('livechat-previous-anonymous-nickname', nick)
+    localStorage.setItem('livechat-previous-anonymous-nickname', nick)
+    localStorage.setItem('livechat-previous-anonymous-nickname-last-access', Date.now().toString())
   } catch (err) {
     console.error(err)
   }