diff --git a/src/fetch.ts b/src/fetch.ts
index c3881d9..0e8fc5b 100644
--- a/src/fetch.ts
+++ b/src/fetch.ts
@@ -77,7 +77,7 @@ export function createFetch ({ fetch }: CreateFetchOptions): $Fetch {
         request = withQuery(request, opts.params)
       }
       const hasPayload = payloadMethods.includes((opts.method || '').toLowerCase())
-      if (opts.body && opts.body.toString() === '[object Object]' && hasPayload) {
+      if (opts.body && typeof opts.body === 'object' && hasPayload) {
         opts.body = JSON.stringify(opts.body)
         setHeader(opts, 'content-type', 'application/json')
       }
diff --git a/test/index.test.mjs b/test/index.test.mjs
index 99bdee3..165f78d 100644
--- a/test/index.test.mjs
+++ b/test/index.test.mjs
@@ -41,6 +41,9 @@ describe('ohmyfetch', () => {
     const { body } = await $fetch(getURL('post'), { method: 'POST', body: { num: 42 } })
     expect(body).to.deep.eq({ num: 42 })
 
+    const body2 = (await $fetch(getURL('post'), { method: 'POST', body: [{ num: 42 }, { num: 43 }] })).body
+    expect(body2).to.deep.eq([{ num: 42 }, { num: 43 }])
+
     const headerFetches = [
       [['Content-Type', 'text/html']],
       [],