diff --git a/tcomb/tcomb-tests.ts b/tcomb/tcomb-tests.ts
index 19ca39b3aa..3a27ffc7fe 100644
--- a/tcomb/tcomb-tests.ts
+++ b/tcomb/tcomb-tests.ts
@@ -256,9 +256,9 @@ describe('update', function () {
         }
       });
 
-      assert.strictEqual(updated[0], instance[0]);
-      assert.notStrictEqual(updated[1], instance[1]);
-      assert.strictEqual(updated[1].c, instance[1].c);
+      assert.strictEqual((<any> updated)[0], (<any> instance)[0]);
+      assert.notStrictEqual((<any> updated)[1], (<any> instance)[1]);
+      assert.strictEqual((<any> updated)[1].c, (<any> instance)[1].c);
     });
   });
 
@@ -1328,8 +1328,8 @@ describe('tuple', function () {
 
     it('should coerce values', function () {
       var t = T([{}, {}]);
-      ok(S.is(t[0]));
-      ok(S.is(t[1]));
+      ok(S.is((<any> t)[0]));
+      ok(S.is((<any> t)[1]));
     });
 
     it('should accept only valid values', function () {
@@ -1381,8 +1381,8 @@ describe('tuple', function () {
     it('should return a new instance', function () {
       var newInstance = Type.update(instance, {0: {$set: 'b'}});
       assert(Type.is(newInstance));
-      assert(instance[0] === 'a');
-      assert(newInstance[0] === 'b');
+      assert((<any> instance)[0] === 'a');
+      assert((<any> newInstance)[0] === 'b');
     });
 
   });
@@ -1418,7 +1418,7 @@ describe('list', function () {
 
     it('should coerce values', function () {
       var t = T([{}]);
-      ok(S.is(t[0]));
+      ok(S.is((<any> t)[0]));
     });
 
     it('should accept only valid values', function () {
diff --git a/tcomb/tcomb.d.ts b/tcomb/tcomb.d.ts
index 91add803a9..1c8825061e 100644
--- a/tcomb/tcomb.d.ts
+++ b/tcomb/tcomb.d.ts
@@ -1,10 +1,13 @@
 // Type definitions for tcomb v1.0.3
 // Project: http://gcanti.github.io/tcomb/guide/index.html
-// Definitions by: Jed Mao <https://github.com/jedmao> and Hans Windhoff <https://github.com/hansrwindhoff>
+// Definitions by: Jed Mao <https://github.com/jedmao>
+//                 and Hans Windhoff <https://github.com/hansrwindhoff>
 // Definitions: https://github.com/borisyankov/DefinitelyTyped
-
 declare module TComb {
 
+  export interface NumbersOnly {
+      [idx:number]:string;
+  }
   export interface tcomb {
     format: (format: string, ...values: any[]) => string;
     getFunctionName: (fn: Function) => string;
@@ -12,7 +15,7 @@ declare module TComb {
     mixin: (target: {}, source: {}, overwrite?: boolean) => any;
     slice: typeof Array.prototype.slice;
     shallowCopy: (x: TCombBase) => TCombBase;
-    update: (instance: any, spec: {}) => TCombBase;
+    update: (instance: any, spec: {} ) => TCombBase;
     assert: (condition: boolean, message?: string, ...values: any[]) => void;
     fail: (message?: string) => void;
     Any: Any_Static;