diff --git a/redlock/redlock-test.ts b/redlock/redlock-test.ts
index e7d61096cd..70a9341a75 100644
--- a/redlock/redlock-test.ts
+++ b/redlock/redlock-test.ts
@@ -86,7 +86,7 @@ module LockTest {
 	{
 		let lock: Lock;
 		let callback: NodeifyCallback<void>;
-		let result: void;
+		let result: Promise<void>;
 		result = lock.unlock();
 		result = lock.unlock(callback);
 	}
diff --git a/redlock/redlock.d.ts b/redlock/redlock.d.ts
index a5dd01be36..4c55f3b621 100644
--- a/redlock/redlock.d.ts
+++ b/redlock/redlock.d.ts
@@ -18,7 +18,7 @@ declare module RedlockTypes {
 		value: any;
 		expiration: number;
 
-		unlock(callback?: NodeifyCallback<void>): void;
+		unlock(callback?: NodeifyCallback<void>): Promise<void>;
 
 		extend(ttl: number, callback?: NodeifyCallback<Lock>): Promise<Lock>;
 	}