diff --git a/knockout/knockout.d.ts b/knockout/knockout.d.ts
index 28d7b94cc4..d439ca3dda 100644
--- a/knockout/knockout.d.ts
+++ b/knockout/knockout.d.ts
@@ -133,8 +133,8 @@ interface KnockoutAllBindingsAccessor {
 }
 
 interface KnockoutBindingHandler {
-    init? (element: any, valueAccessor: () => any, allBindingsAccessor: KnockoutAllBindingsAccessor, viewModel: any, bindingContext: KnockoutBindingContext): void;
-    update? (element: any, valueAccessor: () => any, allBindingsAccessor: KnockoutAllBindingsAccessor, viewModel: any, bindingContext: KnockoutBindingContext): void;
+    init?: (element: any, valueAccessor: () => any, allBindingsAccessor: KnockoutAllBindingsAccessor, viewModel: any, bindingContext: KnockoutBindingContext): void | { controlsDescendantBindings: boolean; };;
+    update?: (element: any, valueAccessor: () => any, allBindingsAccessor: KnockoutAllBindingsAccessor, viewModel: any, bindingContext: KnockoutBindingContext): void;
     options?: any;
     preprocess?: (value: string, name: string, addBindingCallback?: (name: string, value: string) => void) => string;
 }