diff --git a/src/index.ts b/src/index.ts
index 51a1435..6f32264 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -293,24 +293,25 @@ export function stringifySetCookie(
   _val?: string | StringifyOptions,
   _opts?: SerializeOptions,
 ): string {
-  const cookie =
-    typeof _name === "object"
-      ? _name
-      : { ..._opts, name: _name, value: String(_val) };
+  const cookie = typeof _name === "object" ? _name : _opts;
+  const name = typeof _name === "object" ? _name.name : _name;
+  const rawValue = typeof _name === "object" ? _name.value : String(_val);
   const options = typeof _val === "object" ? _val : _opts;
   const enc = options?.encode || encodeURIComponent;
 
-  if (!cookieNameRegExp.test(cookie.name)) {
-    throw new TypeError(`argument name is invalid: ${cookie.name}`);
+  if (!cookieNameRegExp.test(name)) {
+    throw new TypeError(`argument name is invalid: ${name}`);
   }
 
-  const value = cookie.value ? enc(cookie.value) : "";
+  const value = rawValue ? enc(rawValue) : "";
 
   if (!cookieValueRegExp.test(value)) {
-    throw new TypeError(`argument val is invalid: ${cookie.value}`);
+    throw new TypeError(`argument val is invalid: ${rawValue}`);
   }
 
-  let str = cookie.name + "=" + value;
+  let str = name + "=" + value;
+
+  if (!cookie) return str;
 
   if (cookie.maxAge !== undefined) {
     if (!Number.isInteger(cookie.maxAge)) {