diff --git a/threejs/three.d.ts b/threejs/three.d.ts
index a9c33693c8..f7593abe7d 100644
--- a/threejs/three.d.ts
+++ b/threejs/three.d.ts
@@ -5604,7 +5604,7 @@ declare module THREE {
         cone: Mesh;
 
         setDirection(dir: Vector3): void;
-        setLength(length: number): void;
+        setLength(length: number,  headLength?: number, headWidth?: number): void;
         setColor(hex: number): void;
     }