diff --git a/types/define-properties/.editorconfig b/types/define-properties/.editorconfig
new file mode 100644
index 0000000000..a0207fa43b
--- /dev/null
+++ b/types/define-properties/.editorconfig
@@ -0,0 +1,3 @@
+# This package uses tabs
+[*]
+indent_style = tab
diff --git a/types/define-properties/define-properties-tests.ts b/types/define-properties/define-properties-tests.ts
new file mode 100644
index 0000000000..225aead97d
--- /dev/null
+++ b/types/define-properties/define-properties-tests.ts
@@ -0,0 +1,47 @@
+import define = require('define-properties');
+
+declare function __classPrivateFieldGet<T extends object, V>(receiver: T, privateMap: WeakMap<T, V>): V;
+
+const object: object = undefined!;
+const object_foo = new WeakMap<object, string>();
+
+// $ExpectType boolean
+define.supportsDescriptors;
+
+// $ExpectType typeof defineProperties
+define;
+
+// $ExpectError
+define(object);
+
+// $ExpectError
+define(null, {});
+
+define(object, {
+	getFoo() {
+		this; // $ExpectType any
+
+		return __classPrivateFieldGet(this, object_foo);
+	}
+});
+
+define(object, {
+	foo: 'any'
+}, {
+	foo: () => (object as any).foo !== 'any'
+});
+
+// $ExpectError
+define(object, {
+	foo: 'any'
+}, {
+	foo: () => (object as any).foo !== 'any',
+	bar: () => { throw new Error(); },
+});
+
+define(object, {
+	foo: 'any',
+	bar: 'valid'
+}, {
+	foo: () => (object as any).foo !== 'any',
+});
diff --git a/types/define-properties/index.d.ts b/types/define-properties/index.d.ts
new file mode 100644
index 0000000000..563d0f5be6
--- /dev/null
+++ b/types/define-properties/index.d.ts
@@ -0,0 +1,27 @@
+// Type definitions for define-properties 1.1
+// Project: https://github.com/ljharb/define-properties#readme
+// Definitions by: ExE Boss <https://github.com/ExE-Boss>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+declare namespace defineProperties {
+	/**
+	 * Whether the current environment correctly supports property descriptors.
+	 */
+	const supportsDescriptors: boolean;
+}
+
+/**
+ * Defines new properties in `map` as non-enumerable if they don't already
+ * exist on `object`.
+ *
+ * @param object The object to define non-enumerable properties on.
+ * @param map The map of newly defined properties.
+ * @param predicates The optional predicates map, return `true` to override existing properties on `object`.
+ */
+declare function defineProperties<K extends keyof any>(
+	object: object,
+	map: Record<K, any> & ThisType<any>,
+	predicates?: Partial<Record<K, () => boolean>>,
+): void;
+export = defineProperties;
diff --git a/types/define-properties/tsconfig.json b/types/define-properties/tsconfig.json
new file mode 100644
index 0000000000..62880484aa
--- /dev/null
+++ b/types/define-properties/tsconfig.json
@@ -0,0 +1,16 @@
+{
+	"compilerOptions": {
+		"module": "commonjs",
+		"lib": ["es6"],
+		"noImplicitAny": true,
+		"noImplicitThis": true,
+		"strictFunctionTypes": true,
+		"strictNullChecks": true,
+		"baseUrl": "../",
+		"typeRoots": ["../"],
+		"types": [],
+		"noEmit": true,
+		"forceConsistentCasingInFileNames": true
+	},
+	"files": ["index.d.ts", "define-properties-tests.ts"]
+}
diff --git a/types/define-properties/tslint.json b/types/define-properties/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/define-properties/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }