diff --git a/types/p-memoize/index.d.ts b/types/p-memoize/index.d.ts
new file mode 100644
index 0000000000..0b997b4b19
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+++ b/types/p-memoize/index.d.ts
@@ -0,0 +1,56 @@
+// Type definitions for p-memoize 1.0
+// Project: https://github.com/sindresorhus/p-memoize#readme
+// Definitions by: forabi <https://github.com/forabi>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+interface MemOptions {
+    /**
+     * Milliseconds until the cache expires.
+     * @default Infinity
+     */
+    maxAge?: number;
+
+    /**
+     * Determines the cache key for storing the result based on the
+     * function arguments. By default, if there's only one argument and
+     * it's a primitive, it's used directly as a key, otherwise it's all
+     * the function arguments JSON stringified as an array.
+     *
+     * You could for example change it to only cache on the first argument
+     * `x => JSON.stringify(x)`.
+     */
+    cacheKey?: (...args: any[]) => string;
+
+    /**
+     * Use a different cache storage.
+     * Must implement the following methods:
+     * `.has(key)`, `.get(key)`, `.set(key, value)`, `.delete(key)`, and optionally `.clear()`
+     * You could for example use a `WeakMap` instead or `quick-lru` for a LRU cache.
+     *
+     * @default new Map()
+     */
+    cache?: pMemoize.Cache;
+
+    /** Cache rejected promises. */
+    cachePromiseRejection?: boolean;
+}
+
+type PMemoize = <T extends (...args: any[]) => any>(
+    f: T,
+    memoizeOptions?: MemOptions
+) => T;
+
+declare const pMemoize: PMemoize;
+
+declare namespace pMemoize {
+    interface Cache<K = string, V = any> {
+        get(key: K): V;
+        set(key: K, value: V): void;
+        has(key: K): boolean;
+        delete(key: K): void;
+        clear?(): void;
+    }
+}
+
+export = pMemoize;
diff --git a/types/p-memoize/p-memoize-tests.ts b/types/p-memoize/p-memoize-tests.ts
new file mode 100644
index 0000000000..8626482dab
--- /dev/null
+++ b/types/p-memoize/p-memoize-tests.ts
@@ -0,0 +1,13 @@
+import pMemoize = require('p-memoize');
+import { Cache } from 'p-memoize';
+
+const a = pMemoize(async () => Promise.resolve('Hello world!'));
+
+const b = pMemoize(async () => Promise.resolve(1), {
+    maxAge: 1000,
+    cache: new Map()
+});
+
+a();
+
+b();
diff --git a/types/p-memoize/tsconfig.json b/types/p-memoize/tsconfig.json
new file mode 100644
index 0000000000..0605de1be9
--- /dev/null
+++ b/types/p-memoize/tsconfig.json
@@ -0,0 +1,16 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": ["es6"],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": ["../"],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true,
+        "strictFunctionTypes": true
+    },
+    "files": ["index.d.ts", "p-memoize-tests.ts"]
+}
diff --git a/types/p-memoize/tslint.json b/types/p-memoize/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/p-memoize/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }