diff --git a/semaphore/semaphore-tests.ts b/semaphore/semaphore-tests.ts
new file mode 100644
index 000000000..d6df36030
--- /dev/null
+++ b/semaphore/semaphore-tests.ts
@@ -0,0 +1,14 @@
+/// <reference path="semaphore.d.ts"/>
+
+import semaphore = require('semaphore');
+
+var sem: semaphore.Semaphore = semaphore(10);
+
+function task() {
+  console.log('My task');
+  sem.leave();
+}
+
+sem.take(task);
+sem.take(2, task);
+sem.leave(2);
diff --git a/semaphore/semaphore.d.ts b/semaphore/semaphore.d.ts
new file mode 100644
index 000000000..0a2855b82
--- /dev/null
+++ b/semaphore/semaphore.d.ts
@@ -0,0 +1,26 @@
+// Type definitions for semaphore v1.0.3
+// Project: https://github.com/abrkn/semaphore.js
+// Definitions by: Matt Frantz <https://github.com/mhfrantz/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+declare module 'semaphore' {
+
+  function semaphore(capacity?: number): semaphore.Semaphore;
+
+  module semaphore {
+
+    interface Task {
+      (): void;
+    }
+
+    interface Semaphore {
+      capacity: number;
+
+      take(task: Task): void;
+      take(n: number, task: Task): void;
+
+      leave(n?: number): void;
+    }
+  }
+  export = semaphore;
+}