diff --git a/knockout/knockout.d.ts b/knockout/knockout.d.ts
index 512a6a305..006b83361 100644
--- a/knockout/knockout.d.ts
+++ b/knockout/knockout.d.ts
@@ -124,6 +124,7 @@ interface KnockoutBindingContext {
 }
 
 interface KnockoutBindingAccessor {
+    (): any;
     get(name: string): any;
     has(name: string): boolean;
 }