diff --git a/packages/issuer/lib/tokens/index.ts b/packages/issuer/lib/tokens/index.ts
index 06222703..7fe85786 100644
--- a/packages/issuer/lib/tokens/index.ts
+++ b/packages/issuer/lib/tokens/index.ts
@@ -44,11 +44,12 @@ export const generateAccessToken = async (
 ): Promise<string> => {
   const { accessTokenIssuer, alg, accessTokenSignerCallback, tokenExpiresIn, preAuthorizedCode } = opts
   const iat = new Date().getTime()
+  const exp = iat + tokenExpiresIn
   const jwt: Jwt = {
     header: { typ: 'JWT', alg: alg ?? Alg.ES256K },
     payload: {
       iat,
-      exp: tokenExpiresIn,
+      exp,
       iss: accessTokenIssuer,
       ...(preAuthorizedCode && { preAuthorizedCode }),
     },