diff --git a/when/when.d.ts b/when/when.d.ts
index 3b7d114f7..ca2400fc5 100644
--- a/when/when.d.ts
+++ b/when/when.d.ts
@@ -56,6 +56,11 @@ declare module When {
     }
 
     interface Promise<T> {
+        // Make sure you test any usage of these overloads, exceptionType must
+        // be a constructor with prototype set to an instance of Error.
+        catch<U>(exceptionType: any, onRejected?: (reason: any) => Promise<U>): Promise<U>;
+        catch<U>(exceptionType: any, onRejected?: (reason: any) => U): Promise<U>;
+
         catch<U>(filter: (reason: any) => Boolean, onRejected?: (reason: any) => Promise<U>): Promise<U>;
         catch<U>(filter: (reason: any) => Boolean, onRejected?: (reason: any) => U): Promise<U>;