diff --git a/frontend/src/auth.ts b/frontend/src/auth.ts
index f172bff..44d2500 100644
--- a/frontend/src/auth.ts
+++ b/frontend/src/auth.ts
@@ -16,6 +16,8 @@ import {
 } from "@atcute/identity-resolver";
 
 const STORAGE_KEY = "atvouch_did";
+const AUTH_VERSION_KEY = "authVersion";
+const AUTH_VERSION = 1;
 
 export function initOAuth() {
   configureOAuth({
@@ -61,6 +63,7 @@ export async function handleCallback(): Promise<OAuthUserAgent | null> {
   const result = await finalizeAuthorization(params);
   const agent = new OAuthUserAgent(result.session);
   localStorage.setItem(STORAGE_KEY, agent.sub);
+  localStorage.setItem(AUTH_VERSION_KEY, String(AUTH_VERSION));
   return agent;
 }
 
@@ -68,11 +71,19 @@ export async function resumeSession(): Promise<OAuthUserAgent | null> {
   const did = localStorage.getItem(STORAGE_KEY);
   if (!did) return null;
 
+  const storedVersion = parseInt(localStorage.getItem(AUTH_VERSION_KEY) ?? "0", 10);
+  if (storedVersion < AUTH_VERSION) {
+    localStorage.removeItem(STORAGE_KEY);
+    localStorage.removeItem(AUTH_VERSION_KEY);
+    return null;
+  }
+
   try {
     const session = await getSession(did as Did, { allowStale: true });
     return new OAuthUserAgent(session);
   } catch {
     localStorage.removeItem(STORAGE_KEY);
+    localStorage.removeItem(AUTH_VERSION_KEY);
     return null;
   }
 }
@@ -86,4 +97,5 @@ export async function logout(agent: OAuthUserAgent): Promise<void> {
   }
   await deleteStoredSession(did);
   localStorage.removeItem(STORAGE_KEY);
+  localStorage.removeItem(AUTH_VERSION_KEY);
 }