diff --git a/promise.js b/promise.js
index c1a0b72..8254fc8 100644
--- a/promise.js
+++ b/promise.js
@@ -27,11 +27,12 @@ export const createEmpty = f => new Promise(f)
 
 /**
  * `Promise.all` wait for all promises in the array to resolve and return the result
- * @template T
- * @param {Array<Promise<T>>} arrp
- * @return {Promise<Array<T>>}
+ * @template {unknown[] | []} PS
+ *
+ * @param {PS} ps
+ * @return {Promise<{ -readonly [P in keyof PS]: Awaited<PS[P]> }>}
  */
-export const all = arrp => Promise.all(arrp)
+export const all = Promise.all.bind(Promise)
 
 /**
  * @param {Error} [reason]
diff --git a/promise.test.js b/promise.test.js
index 66212b5..4aebb6b 100644
--- a/promise.test.js
+++ b/promise.test.js
@@ -25,9 +25,9 @@ const measureP = (p, min, max) => {
 const failsP = p => promise.create((resolve, reject) => p.then(() => reject(error.create('Promise should fail')), resolve))
 
 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
  */
-export const testRepeatPromise = async tc => {
+export const testRepeatPromise = async _tc => {
   t.assert(promise.createEmpty(r => r()).constructor === Promise, 'p.create() creates a Promise')
   t.assert(promise.resolve().constructor === Promise, 'p.reject() creates a Promise')
   const rejectedP = promise.reject()
@@ -44,9 +44,9 @@ export const testRepeatPromise = async tc => {
 }
 
 /**
- * @param {t.TestCase} tc
+ * @param {t.TestCase} _tc
  */
-export const testispromise = tc => {
+export const testispromise = _tc => {
   t.assert(promise.isPromise(new Promise(() => {})))
   t.assert(promise.isPromise(promise.create(() => {})))
   const rej = promise.reject()
@@ -58,3 +58,19 @@ export const testispromise = tc => {
     t.assert(promise.isPromise({ then: () => {}, catch: () => {} }))
   })
 }
+
+/**
+ * @param {t.TestCase} _tc
+ */
+export const testTypings = async _tc => {
+  const ps = await promise.all([promise.resolveWith(4), 'string'])
+  /**
+   * @type {number}
+   */
+  const a = ps[0]
+  /**
+   * @type {string}
+   */
+  const b = ps[1]
+  t.assert(typeof a === 'number' && typeof b === 'string')
+}