diff --git a/src/index.ts b/src/index.ts
index ffc89dd..a2123d0 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -22,7 +22,7 @@ export interface JWTPayloadSpec {
 	aud?: string | string[]
 	jti?: string
 	nbf?: number
-	exp?: number
+	exp?: number | string
 	iat?: number
 }
 
@@ -145,6 +145,7 @@ JWTOption<Name, Schema>) => {
 
 			if (nbf) jwt = jwt.setNotBefore(nbf)
 			if (exp) jwt = jwt.setExpirationTime(exp)
+			if (morePayload.exp) jwt = jwt.setExpirationTime(morePayload.exp)
 
 			return jwt.sign(key)
 		},