diff --git a/when/when.d.ts b/when/when.d.ts
index 56d8833562..859618852a 100644
--- a/when/when.d.ts
+++ b/when/when.d.ts
@@ -56,11 +56,25 @@ declare module When {
     }
 
     interface Promise<T> {
+        catch<U>(onRejected?: (reason: any) => Promise<U>): Promise<U>;
+        catch<U>(onRejected?: (reason: any) => U): Promise<U>;
+
         ensure(onFulfilledOrRejected: Function): Promise<T>;
 
+        inspect(): Snapshot<T>;
+
+        otherwise<U>(onRejected?: (reason: any) => Promise<U>): Promise<U>;
+        otherwise<U>(onRejected?: (reason: any) => U): Promise<U>;
+
         then<U>(onFulfilled: (value: T) => Promise<U>, onRejected?: (reason: any) => Promise<U>, onProgress?: (update: any) => void): Promise<U>;
         then<U>(onFulfilled: (value: T) => Promise<U>, onRejected?: (reason: any) => U, onProgress?: (update: any) => void): Promise<U>;
         then<U>(onFulfilled: (value: T) => U, onRejected?: (reason: any) => Promise<U>, onProgress?: (update: any) => void): Promise<U>;
         then<U>(onFulfilled: (value: T) => U, onRejected?: (reason: any) => U, onProgress?: (update: any) => void): Promise<U>;
     }
+
+    interface Snapshot<T> {
+        state: string;
+        value?: T;
+        reason?: any;
+    }
 }