diff --git a/package.json b/package.json
index c503294..57ed666 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
     "@types/ioredis": "^4.0.18",
     "@types/moment-precise-range-plugin": "^0.2.0",
     "@types/mongoose": "^5.5.20",
+    "@types/node": "^13.9.1",
     "@types/nodemailer": "^6.2.1",
     "@types/signale": "^1.2.1",
     "@types/uuid": "^3.4.5",
diff --git a/types/global.d.ts b/types/global.d.ts
new file mode 100644
index 0000000..04a9dd5
--- /dev/null
+++ b/types/global.d.ts
@@ -0,0 +1,31 @@
+
+interface PromiseFulfilledResult<T> {
+  status: 'fulfilled';
+  value: T;
+}
+
+interface PromiseRejectedResult {
+  status: 'rejected';
+  reason: any;
+}
+
+type PromiseSettledResult<T> = PromiseFulfilledResult<T> | PromiseRejectedResult;
+
+interface PromiseConstructor {
+  /**
+   * Creates a Promise that is resolved with an array of results when all
+   * of the provided Promises resolve or reject.
+   * @param values An array of Promises.
+   * @returns A new Promise.
+   */
+  allSettled<T extends readonly unknown[] | readonly [unknown]>(values: T):
+      Promise<{ -readonly [P in keyof T]: PromiseSettledResult<T[P] extends PromiseLike<infer U> ? U : T[P]> }>;
+
+  /**
+   * Creates a Promise that is resolved with an array of results when all
+   * of the provided Promises resolve or reject.
+   * @param values An array of Promises.
+   * @returns A new Promise.
+   */
+  allSettled<T>(values: Iterable<T>): Promise<PromiseSettledResult<T extends PromiseLike<infer U> ? U : T>[]>;
+}