diff --git a/.changeset/warm-pets-sin.md b/.changeset/warm-pets-sin.md
new file mode 100644
index 0000000000..3a9197e7f2
--- /dev/null
+++ b/.changeset/warm-pets-sin.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-auth-backend': patch
+---
+
+fix bug in token expiration date
diff --git a/plugins/auth-backend/src/identity/TokenFactory.test.ts b/plugins/auth-backend/src/identity/TokenFactory.test.ts
index 4303401ee6..8b719799b1 100644
--- a/plugins/auth-backend/src/identity/TokenFactory.test.ts
+++ b/plugins/auth-backend/src/identity/TokenFactory.test.ts
@@ -87,7 +87,7 @@ describe('TokenFactory', () => {
       iat: expect.any(Number),
       exp: expect.any(Number),
     });
-    expect(payload.exp).toBe(payload.iat + keyDurationSeconds * 1000);
+    expect(payload.exp).toBe(payload.iat + keyDurationSeconds);
   });
 
   it('should generate new signing keys when the current one expires', async () => {
diff --git a/plugins/auth-backend/src/identity/TokenFactory.ts b/plugins/auth-backend/src/identity/TokenFactory.ts
index c4c259ed22..36622332e0 100644
--- a/plugins/auth-backend/src/identity/TokenFactory.ts
+++ b/plugins/auth-backend/src/identity/TokenFactory.ts
@@ -69,7 +69,7 @@ export class TokenFactory implements TokenIssuer {
     const sub = params.claims.sub;
     const aud = 'backstage';
     const iat = Math.floor(Date.now() / MS_IN_S);
-    const exp = iat + this.keyDurationSeconds * MS_IN_S;
+    const exp = iat + this.keyDurationSeconds;
 
     this.logger.info(`Issuing token for ${sub}`);