diff --git a/simplestorage.js/simplestorage.js-tests.ts b/simplestorage.js/simplestorage.js-tests.ts
index 1e9f4202a3..4106c88001 100644
--- a/simplestorage.js/simplestorage.js-tests.ts
+++ b/simplestorage.js/simplestorage.js-tests.ts
@@ -1,17 +1,18 @@
 ///<reference path="simplestorage.js.d.ts"/>
 
-var versionTest:        string           = simpleStorage.version;
-var canUseTest:         boolean          = simpleStorage.canUse();
-var simpleStorageTest1: boolean|Error    = simpleStorage.set("string", 7);
-var simpleStorageTest2: boolean|Error    = simpleStorage.set("string", 7, {});
-var simpleStorageTest3: boolean|Error    = simpleStorage.set("string", 7, { TTL: 7 });
-var simpleStorageTest4: boolean|Error    = simpleStorage.set("string", undefined);
-var simpleStorageTest5: boolean|Error    = simpleStorage.set("string", undefined, {});
-var simpleStorageTest6: boolean|Error    = simpleStorage.set("string", undefined, { TTL: 7 });
-var getTest:            any              = simpleStorage.get("string");
-var deleteKeyTest:      boolean|Error    = simpleStorage.deleteKey("string");
-var setTTLTest:         boolean|Error    = simpleStorage.setTTL("string", 7);
-var getTTLTest:         number|boolean   = simpleStorage.getTTL("string");
-var flushTest:          boolean|Error    = simpleStorage.flush();
-var indexTest:          [string]|boolean = simpleStorage.index();
-var storageSizeTest:    number           = simpleStorage.storageSize();
+var versionTest: string = simpleStorage.version;
+var canUseTest: boolean = simpleStorage.canUse();
+var simpleStorageTest1: boolean|Error = simpleStorage.set("string", 7);
+var simpleStorageTest2: boolean|Error = simpleStorage.set("string", 7, {});
+var simpleStorageTest3: boolean|Error = simpleStorage.set("string", 7, {TTL: 7});
+var simpleStorageTest4: boolean|Error = simpleStorage.set("string", undefined);
+var simpleStorageTest5: boolean|Error = simpleStorage.set("string", undefined, {});
+var simpleStorageTest6: boolean|Error = simpleStorage.set("string", undefined, {TTL: 7});
+var getTest: any = simpleStorage.get("string");
+var deleteKeyTest: boolean|Error = simpleStorage.deleteKey("string");
+var setTTLTest: boolean|Error = simpleStorage.setTTL("string", 7);
+var getTTLTest: number|boolean = simpleStorage.getTTL("string");
+var flushTest: boolean|Error = simpleStorage.flush();
+var indexTest: [string]|boolean = simpleStorage.index();
+var storageSizeTest: number = simpleStorage.storageSize();
+var hasKey: boolean = simpleStorage.hasKey("string");
diff --git a/simplestorage.js/simplestorage.js.d.ts b/simplestorage.js/simplestorage.js.d.ts
index 43650fd657..9e02f1b454 100644
--- a/simplestorage.js/simplestorage.js.d.ts
+++ b/simplestorage.js/simplestorage.js.d.ts
@@ -1,6 +1,6 @@
-// Type definitions for simpleStorage v0.1.3
+// Type definitions for simplestorage.js v0.2.1
 // Project: https://github.com/andris9/simpleStorage
-// Definitions by: Áxel Costas Pena <https://github.com/axelcostaspena>
+// Definitions by: Áxel Costas Pena <https://github.com/axelcostaspena>, Michael Ledin <https://github.com/mxl>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 declare namespace simplestoragejs {
@@ -38,6 +38,14 @@ declare namespace simplestoragejs {
          */
         get(key: string): any;
 
+        /**
+         * Checks if there's a value with the given key in the local storage.
+         * Returns <code>true</code> if the given key exists, <code>false</code> otherwise.
+         * @param key The key to be checked.
+         * @see https://github.com/andris9/simpleStorage#haskeykey
+         */
+        hasKey(key: string): boolean;
+
         /**
          * Removes a value from local storage.
          * Returns <code>true</code> if the value was deleted, <code>false</code> if the value was not found or <code>{@link Error}</code> object if value was not deleted because of an error.
@@ -96,7 +104,7 @@ declare namespace simplestoragejs {
 
 }
 
-declare module "simpleStorage" {
+declare module "simplestorage.js" {
     export = simpleStorage;
 }
 
@@ -107,4 +115,4 @@ declare module "simpleStorage" {
  * {@link simpleStorage} is very small - about 1kB in size when minimized and gzipped.
  * @see https://github.com/andris9/simpleStorage#simplestorage
  */
-declare var simpleStorage:simplestoragejs.SimpleStorage;
+declare var simpleStorage: simplestoragejs.SimpleStorage;