diff --git a/index.d.ts b/index.d.ts
index 77e0fa3..845ceaa 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,12 +1,21 @@
-/**
-Get the visual width of the widest line in a string - the number of columns required to display it.
-
-@example
-```
-import widestLine from 'widest-line';
-
-widestLine('古\n\u001B[1m@\u001B[22m');
-//=> 2
-```
-*/
-export default function widestLine(input: string): number;
+declare const widestLine: {
+	/**
+	Get the visual width of the widest line in a string - the number of columns required to display it.
+
+	@example
+	```
+	import widestLine = require('widest-line');
+
+	widestLine('古\n\u001B[1m@\u001B[22m');
+	//=> 2
+	```
+	*/
+	(input: string): number;
+
+	// TODO: remove this in the next major version, refactor definition to:
+	// declare function widestLine(input: string): number;
+	// export = widestLine;
+	default: typeof widestLine;
+};
+
+export = widestLine;
diff --git a/index.js b/index.js
index f49a3a8..98f8ce4 100644
--- a/index.js
+++ b/index.js
@@ -12,4 +12,5 @@ const widestLine = input => {
 };
 
 module.exports = widestLine;
+// TODO: remove this in the next major version
 module.exports.default = widestLine;
diff --git a/index.test-d.ts b/index.test-d.ts
index e9a5477..c036faf 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -1,4 +1,4 @@
-import {expectType} from 'tsd-check';
-import widestLine from '.';
+import {expectType} from 'tsd';
+import widestLine = require('.');
 
 expectType<number>(widestLine('古\n\u001B[1m@\u001B[22m'));
diff --git a/package.json b/package.json
index 388e4ed..a32fbef 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
 		"node": ">=8"
 	},
 	"scripts": {
-		"test": "xo && ava && tsd-check"
+		"test": "xo && ava && tsd"
 	},
 	"files": [
 		"index.js",
@@ -47,8 +47,8 @@
 		"string-width": "^4.0.0"
 	},
 	"devDependencies": {
-		"ava": "^1.3.1",
-		"tsd-check": "^0.5.0",
+		"ava": "^1.4.1",
+		"tsd": "^0.7.1",
 		"xo": "^0.24.0"
 	}
 }