diff --git a/v1/index.d.ts b/v1/index.d.ts
index e37a1e8..f54d219 100644
--- a/v1/index.d.ts
+++ b/v1/index.d.ts
@@ -2,7 +2,7 @@
  * CloudEvent class definition
  */
 export class Cloudevent {
-  public constructor();
+  public constructor(spec?: any, formatter?: any);
 
   public format(): any;
   public toString(): string;