diff --git a/api/@ohos.util.d.ets b/api/@ohos.util.d.ets
index 72a794baa4a330fc1507e7cfb06dfb8234b6d766..03b4f1def245d3aa08a6aeeee977d06fc47a7481 100644
--- a/api/@ohos.util.d.ets
+++ b/api/@ohos.util.d.ets
@@ -1442,6 +1442,19 @@ declare namespace util {
     isWeakSet(value: Object): boolean;
   }
 
+  /**
+   * Takes a function following the common error-first callback style, i.e taking an (err, value) =>
+   * callback as the last argument, and return a function that returns promises.
+   *
+   * @param { Function } original - Asynchronous Function
+   * @returns { Function } Return a function that returns promises
+   * @syscap SystemCapability.Utils.Lang
+   * @crossplatform
+   * @atomicservice
+   * @since 20
+   */
+  function promisify(original: Function): (...args: FixedArray<Any>) => Promise<Any>;
+
   /**
    * Get the hash code of an object.
    *