diff --git a/types/proper-lockfile/index.d.ts b/types/proper-lockfile/index.d.ts
index 3e49e79fe3..85a5267791 100644
--- a/types/proper-lockfile/index.d.ts
+++ b/types/proper-lockfile/index.d.ts
@@ -1,13 +1,17 @@
-// Type definitions for proper-lockfile 3.0
+// Type definitions for proper-lockfile 4.1
 // Project: https://github.com/moxystudio/node-proper-lockfile
 // Definitions by: Nikita Volodin <https://github.com/qlonik>
 //                 Linus Unnebäck <https://github.com/LinusU>
+//                 ulrichb <https://github.com/ulrichb>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+import { TimeoutsOptions } from "retry";
 
 export interface LockOptions {
     stale?: number; // default: 10000
     update?: number; // default: stale/2
-    retries?: number; // default: 0
+    retries?: number | TimeoutsOptions; // default: 0
     realpath?: boolean; // default: true
     fs?: any; // default: graceful-fs
     onCompromised?: (err: Error) => any; // default: (err) => throw err
diff --git a/types/proper-lockfile/proper-lockfile-tests.ts b/types/proper-lockfile/proper-lockfile-tests.ts
index 344e7be3f8..a4970ced40 100644
--- a/types/proper-lockfile/proper-lockfile-tests.ts
+++ b/types/proper-lockfile/proper-lockfile-tests.ts
@@ -48,3 +48,6 @@ unlockSync('some/file'); // $ExpectType void
 unlockSync('', { lockfilePath: 'some/file-lock' }); // $ExpectType void
 checkSync('some/file'); // $ExpectType boolean
 checkSync('', { lockfilePath: 'some/file-lock' }); // $ExpectType boolean
+
+lock('', { retries: 5 });
+lock('', { retries: { retries: 5, factor: 2, minTimeout: 100, randomize: true } });