diff --git a/types/power-assert/index.d.ts b/types/power-assert/index.d.ts
index f8b3cc828b..2039512f70 100644
--- a/types/power-assert/index.d.ts
+++ b/types/power-assert/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for power-assert 1.5.2
+// Type definitions for power-assert 1.5.3
 // Project: https://github.com/twada/power-assert
 // Definitions by: vvakame <https://github.com/vvakame>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
diff --git a/types/power-assert/package.json b/types/power-assert/package.json
deleted file mode 100644
index 4060baedd2..0000000000
--- a/types/power-assert/package.json
+++ /dev/null
@@ -1,11 +0,0 @@
-{
-    "private": true,
-    "types": "index",
-    "typesVersions": {
-        ">=3.7.0-0": {
-            "*": [
-                "ts3.7/*"
-            ]
-        }
-    }
-}
\ No newline at end of file
diff --git a/types/power-assert/power-assert-tests.ts b/types/power-assert/power-assert-tests.ts
index a60f99964d..5f95493508 100644
--- a/types/power-assert/power-assert-tests.ts
+++ b/types/power-assert/power-assert-tests.ts
@@ -85,3 +85,8 @@ var customizedAssert2 = assert.customize({
 });
 
 (): typeof assert => assert.strict;
+
+declare const set: Set<0>;
+assert(set.size === 0);
+set.add(0);
+assert(set.size === 1);
diff --git a/types/power-assert/ts3.7/index.d.ts b/types/power-assert/ts3.7/index.d.ts
deleted file mode 100644
index ec24a3b4b7..0000000000
--- a/types/power-assert/ts3.7/index.d.ts
+++ /dev/null
@@ -1,61 +0,0 @@
-// Type definitions for power-assert 1.5.2
-// Project: https://github.com/twada/power-assert
-// Definitions by: vvakame <https://github.com/vvakame>
-// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-
-// copy from assert external module in node.d.ts
-
-/// <reference types="empower" />
-/// <reference types="power-assert-formatter" />
-
-import * as empower from "empower";
-
-export = assert;
-export as namespace assert;
-
-declare function assert(value: any, message?: string): asserts value;
-declare namespace assert {
-    export class AssertionError implements Error {
-        name: string;
-        message: string;
-        actual: any;
-        expected: any;
-        operator: string;
-        generatedMessage: boolean;
-
-        constructor(options?: { message?: string; actual?: any; expected?: any; operator?: string; stackStartFunction?: Function });
-    }
-
-    export function fail(actual?: any, expected?: any, message?: string, operator?: string): never;
-    export function ok(value: any, message?: string): asserts value;
-    export function equal(actual: any, expected: any, message?: string): void;
-    export function notEqual(actual: any, expected: any, message?: string): void;
-    export function deepEqual(actual: any, expected: any, message?: string): void;
-    export function notDeepEqual(acutal: any, expected: any, message?: string): void;
-    export function strictEqual(actual: any, expected: any, message?: string): void;
-    export function notStrictEqual(actual: any, expected: any, message?: string): void;
-    export function deepStrictEqual(actual: any, expected: any, message?: string): void;
-    export function notDeepStrictEqual(actual: any, expected: any, message?: string): void;
-    export var throws: {
-        (block: Function, message?: string): void;
-        (block: Function, error: Function, message?: string): void;
-        (block: Function, error: RegExp, message?: string): void;
-        (block: Function, error: (err: any) => boolean, message?: string): void;
-    };
-    export var doesNotThrow: {
-        (block: Function, message?: string): void;
-        (block: Function, error: Function, message?: string): void;
-        (block: Function, error: RegExp, message?: string): void;
-        (block: Function, error: (err: any) => boolean, message?: string): void;
-    };
-    export function ifError(value: any): void;
-
-    export const strict: typeof assert;
-
-    export interface Options {
-        assertion?: empower.Options;
-        output?: powerAssertFormatter.Options;
-    }
-
-    export function customize(options: Options): typeof assert;
-}
diff --git a/types/power-assert/ts3.7/tsconfig.json b/types/power-assert/ts3.7/tsconfig.json
deleted file mode 100644
index 26ac51fe84..0000000000
--- a/types/power-assert/ts3.7/tsconfig.json
+++ /dev/null
@@ -1,23 +0,0 @@
-{
-    "extends": "../tsconfig",
-    "compilerOptions": {
-        "module": "commonjs",
-        "lib": [
-            "es6"
-        ],
-        "noImplicitAny": true,
-        "noImplicitThis": true,
-        "strictNullChecks": false,
-        "strictFunctionTypes": true,
-        "baseUrl": "../../",
-        "typeRoots": [
-            "../../"
-        ],
-        "types": [],
-        "noEmit": true,
-        "forceConsistentCasingInFileNames": true
-    },
-    "files": [
-        "index.d.ts"
-    ]
-}
diff --git a/types/power-assert/ts3.7/tslint.json b/types/power-assert/ts3.7/tslint.json
deleted file mode 100644
index 3d59f55fda..0000000000
--- a/types/power-assert/ts3.7/tslint.json
+++ /dev/null
@@ -1,80 +0,0 @@
-{
-    "extends": "dtslint/dt.json",
-    "rules": {
-        "adjacent-overload-signatures": false,
-        "array-type": false,
-        "arrow-return-shorthand": false,
-        "ban-types": false,
-        "callable-types": false,
-        "comment-format": false,
-        "dt-header": false,
-        "npm-naming": false,
-        "eofline": false,
-        "export-just-namespace": false,
-        "import-spacing": false,
-        "interface-name": false,
-        "interface-over-type-literal": false,
-        "jsdoc-format": false,
-        "max-line-length": false,
-        "member-access": false,
-        "new-parens": false,
-        "no-any-union": false,
-        "no-boolean-literal-compare": false,
-        "no-conditional-assignment": false,
-        "no-consecutive-blank-lines": false,
-        "no-construct": false,
-        "no-declare-current-package": false,
-        "no-duplicate-imports": false,
-        "no-duplicate-variable": false,
-        "no-empty-interface": false,
-        "no-for-in-array": false,
-        "no-inferrable-types": false,
-        "no-internal-module": false,
-        "no-irregular-whitespace": false,
-        "no-mergeable-namespace": false,
-        "no-misused-new": false,
-        "no-namespace": false,
-        "no-object-literal-type-assertion": false,
-        "no-padding": false,
-        "no-redundant-jsdoc": false,
-        "no-redundant-jsdoc-2": false,
-        "no-redundant-undefined": false,
-        "no-reference-import": false,
-        "no-relative-import-in-test": false,
-        "no-self-import": false,
-        "no-single-declare-module": false,
-        "no-string-throw": false,
-        "no-unnecessary-callback-wrapper": false,
-        "no-unnecessary-class": false,
-        "no-unnecessary-generics": false,
-        "no-unnecessary-qualifier": false,
-        "no-unnecessary-type-assertion": false,
-        "no-useless-files": false,
-        "no-var-keyword": false,
-        "no-var-requires": false,
-        "no-void-expression": false,
-        "no-trailing-whitespace": false,
-        "object-literal-key-quotes": false,
-        "object-literal-shorthand": false,
-        "one-line": false,
-        "one-variable-per-declaration": false,
-        "only-arrow-functions": false,
-        "prefer-conditional-expression": false,
-        "prefer-const": false,
-        "prefer-declare-function": false,
-        "prefer-for-of": false,
-        "prefer-method-signature": false,
-        "prefer-template": false,
-        "radix": false,
-        "semicolon": false,
-        "space-before-function-paren": false,
-        "space-within-parens": false,
-        "strict-export-declare-modifiers": false,
-        "trim-file": false,
-        "triple-equals": false,
-        "typedef-whitespace": false,
-        "unified-signatures": false,
-        "void-return": false,
-        "whitespace": false
-    }
-}